diff --git a/module_usb_aud_shared/usb_buffer/decouple.xc b/module_usb_aud_shared/usb_buffer/decouple.xc
index fd59d611..9e9640d0 100644
--- a/module_usb_aud_shared/usb_buffer/decouple.xc
+++ b/module_usb_aud_shared/usb_buffer/decouple.xc
@@ -675,6 +675,8 @@ void decouple(chanend c_mix_out,
     int iap_waiting_on_send_to_host = 0;
     int iap_to_host_flag = 0;
     int iap_from_host_flag = 0;
+    int iap_expecting_length = 1;
+    int iap_expecting_data_length = 0;
 #endif
 
     int t = array_to_xc_ptr(outAudioBuff);
@@ -1168,6 +1170,7 @@ void decouple(chanend c_mix_out,
         if (iap_reset) {
            iap_send_reset(c_iap); // What if this happen in the middle of a send/ack?
            iap_reset = 0;
+           iap_expecting_length = 1;
            SET_SHARED_GLOBAL(g_iap_reset, iap_reset); // Reset has been signalled
         }
         // Need to handle sending ZLP on iap_to_host_usb_ep_int to signal iOS device to collect from bulk endpoint.
@@ -1209,30 +1212,30 @@ void decouple(chanend c_mix_out,
                 /* The buffer() thread has filled up a buffer */
                 /* Reset flag */
                 SET_SHARED_GLOBAL(g_iap_from_host_flag, 0);
-           
+
                 /* Read length from buffer[0] */
                 read_via_xc_ptr(iap_data_remaining_to_device, iap_from_host_buffer);
 
                 // Send length first so iAP thread knows how much data to expect
                 // Don't expect ack from this to make it simpler
                 outuint(c_iap, iap_data_remaining_to_device);
-            
+
                 /* Increment read pointer - buffer[0] is length */
                 iap_from_host_rdptr = iap_from_host_buffer + 4;
-           
+
                 if (iap_data_remaining_to_device) 
                 {
                     read_byte_via_xc_ptr(datum_iap, iap_from_host_rdptr);
                     outuint(c_iap, datum_iap);
                     iap_from_host_rdptr += 1;
                     iap_data_remaining_to_device -= 1;
-                }                        
+                }
              }
         }
-   
+
         select 
-        {   
-            /* Received word from iap thread - Check for ACK or Data */                 
+        {
+            /* Received word from iap thread - Check for ACK or Data */
             case iap_get_ack_or_reset_or_data(c_iap, is_ack_iap, is_reset, datum_iap):
                 if (is_ack_iap) 
                 {
@@ -1241,7 +1244,7 @@ void decouple(chanend c_mix_out,
                     if (iap_data_remaining_to_device == 0) 
                     {
                         /* We have read an entire packet - Mark ready to receive another */
-                        XUD_SetReady(iap_from_host_usb_ep, 1);              
+                        XUD_SetReady(iap_from_host_usb_ep, 1);
                     }
                     else 
                     {
@@ -1250,40 +1253,46 @@ void decouple(chanend c_mix_out,
                         outuint(c_iap, datum_iap);
                         iap_from_host_rdptr += 1;
                         iap_data_remaining_to_device -= 1;
-                    }         
+                    }
                 }
-                else 
+                else
                 {
                     /* The iap/uart thread has sent us some data - handshake back */
                     iap_send_ack(c_iap);
-                    if (iap_data_collected_from_device < IAP_USB_BUFFER_TO_HOST_SIZE)
-                    {
-                        /* There is room in the collecting buffer for the data */
-                        xc_ptr p = (iap_to_host_buffer_being_collected + 4) + iap_data_collected_from_device;                                                            
-                        // Add data to the buffer
-                        write_byte_via_xc_ptr(p, datum_iap);
-                        iap_data_collected_from_device += 1;
+                    if (iap_expecting_length) {
+                       iap_expecting_data_length = datum_iap;
+                       iap_expecting_length = 0;
+                    } else {
+                       if (iap_data_collected_from_device < IAP_USB_BUFFER_TO_HOST_SIZE)
+                       {
+                           /* There is room in the collecting buffer for the data */
+                           xc_ptr p = (iap_to_host_buffer_being_collected + 4) + iap_data_collected_from_device;
+                           // Add data to the buffer
+                           write_byte_via_xc_ptr(p, datum_iap);
+                           iap_data_collected_from_device += 1;
+                       }
+                       else 
+                       {
+                           // Too many events from device - drop 
+                       } 
+
+                       // If we are not sending data to the host then initiate it (ONLY IF GOT WHOLE MESSAGE)
+                       if (!iap_waiting_on_send_to_host && (iap_data_collected_from_device == iap_expecting_data_length)) 
+                       {
+                           // Set first element of buffer to length i.e. iap_to_host_buffer_being_collected[0] = iap_data_collected_from_device;
+                           write_via_xc_ptr(iap_to_host_buffer_being_collected, iap_data_collected_from_device);
+
+                           swap(iap_to_host_buffer_being_collected, iap_to_host_buffer_being_sent);
+
+                           // Signal other side to swap
+                           XUD_SetReady_In(iap_to_host_int_usb_ep, 0, zero_buffer, 0);
+                           XUD_SetReady_In(iap_to_host_usb_ep, 0, iap_to_host_buffer_being_sent+4, iap_data_collected_from_device);
+                           iap_data_collected_from_device = 0;
+                           iap_waiting_on_send_to_host = 1;
+                           iap_expecting_length = 1;
+                       }
                     }
-                    else 
-                    {
-                        // Too many events from device - drop 
-                    } 
-                
-                    // If we are not sending data to the host then initiate it
-                    if (!iap_waiting_on_send_to_host) 
-                    {
-                        // Set first element of buffer to length i.e. iap_to_host_buffer_being_collected[0] = iap_data_collected_from_device;
-                        write_via_xc_ptr(iap_to_host_buffer_being_collected, iap_data_collected_from_device);
-                    
-                        swap(iap_to_host_buffer_being_collected, iap_to_host_buffer_being_sent);
-                    
-                        // Signal other side to swap
-                        XUD_SetReady_In(iap_to_host_int_usb_ep, 0, zero_buffer, 0);
-                        XUD_SetReady_In(iap_to_host_usb_ep, 0, iap_to_host_buffer_being_sent+4, iap_data_collected_from_device);
-                        iap_data_collected_from_device = 0;
-                        iap_waiting_on_send_to_host = 1;                  
-                    }
-                }          
+                }
                 break;
             default:
                 break;