diff --git a/LUFA/DoxygenPages/ChangeLog.txt b/LUFA/DoxygenPages/ChangeLog.txt
index 271c23d10b..e92f026cf0 100644
--- a/LUFA/DoxygenPages/ChangeLog.txt
+++ b/LUFA/DoxygenPages/ChangeLog.txt
@@ -34,6 +34,8 @@
   *  - Library Applications:
   *   - Fixed broken RESET_TOGGLES_LIBUSB_COMPAT compile time option in the AVRISP-MKII project
   *   - Fixed incompatibility in the CDC class bootloader on some systems (thanks to Sylvain Munaut)
+  *   - Fixed lengthy timeouts in the USBtoSerial project if no application on the host is consuming data (thanks to Nicolas Saugnier)
+  *   - Fixed lengthy automatic data flushing in the CDC and MIDI device class drivers
   *
   *  \section Sec_ChangeLog120730 Version 120730
   *  <b>New:</b>
diff --git a/LUFA/Drivers/USB/Class/Device/CDCClassDevice.c b/LUFA/Drivers/USB/Class/Device/CDCClassDevice.c
index ff0f9bb552..61f4be9d76 100644
--- a/LUFA/Drivers/USB/Class/Device/CDCClassDevice.c
+++ b/LUFA/Drivers/USB/Class/Device/CDCClassDevice.c
@@ -138,7 +138,10 @@ void CDC_Device_USBTask(USB_ClassInfo_CDC_Device_t* const CDCInterfaceInfo)
 	  return;
 
 	#if !defined(NO_CLASS_DRIVER_AUTOFLUSH)
-	CDC_Device_Flush(CDCInterfaceInfo);
+	Endpoint_SelectEndpoint(CDCInterfaceInfo->Config.DataINEndpoint.Address);
+	
+	if (Endpoint_IsINReady())
+	  CDC_Device_Flush(CDCInterfaceInfo);
 	#endif
 }
 
diff --git a/LUFA/Drivers/USB/Class/Device/MIDIClassDevice.c b/LUFA/Drivers/USB/Class/Device/MIDIClassDevice.c
index c9553a4135..5defa142aa 100644
--- a/LUFA/Drivers/USB/Class/Device/MIDIClassDevice.c
+++ b/LUFA/Drivers/USB/Class/Device/MIDIClassDevice.c
@@ -59,7 +59,10 @@ void MIDI_Device_USBTask(USB_ClassInfo_MIDI_Device_t* const MIDIInterfaceInfo)
 	  return;
 
 	#if !defined(NO_CLASS_DRIVER_AUTOFLUSH)
-	MIDI_Device_Flush(MIDIInterfaceInfo);
+	Endpoint_SelectEndpoint(MIDIInterfaceInfo->Config.DataINEndpoint.Address);
+	
+	if (Endpoint_IsINReady())
+	  MIDI_Device_Flush(MIDIInterfaceInfo);
 	#endif
 }
 
diff --git a/Projects/USBtoSerial/USBtoSerial.c b/Projects/USBtoSerial/USBtoSerial.c
index 7fe67da447..a0b8de4c4e 100644
--- a/Projects/USBtoSerial/USBtoSerial.c
+++ b/Projects/USBtoSerial/USBtoSerial.c
@@ -108,21 +108,32 @@ int main(void)
 		uint16_t BufferCount = RingBuffer_GetCount(&USARTtoUSB_Buffer);
 		if ((TIFR0 & (1 << TOV0)) || (BufferCount > (uint8_t)(sizeof(USARTtoUSB_Buffer_Data) * .75)))
 		{
-			/* Clear flush timer expiry flag */
-			TIFR0 |= (1 << TOV0);
-
-			/* Read bytes from the USART receive buffer into the USB IN endpoint */
-			while (BufferCount--)
+			Endpoint_SelectEndpoint(VirtualSerial_CDC_Interface.Config.DataINEndpoint.Address);
+			
+			/* Check if a packet is already enqueued to the host - if so, we shouldn't try to send more data
+			 * until it completes as there is a chance nothing is listening and a lengthy timeout could occur */
+			if (Endpoint_IsINReady())
 			{
-				/* Try to send the next byte of data to the host, abort if there is an error without dequeuing */
-				if (CDC_Device_SendByte(&VirtualSerial_CDC_Interface,
-				                        RingBuffer_Peek(&USARTtoUSB_Buffer)) != ENDPOINT_READYWAIT_NoError)
+				/* Clear flush timer expiry flag */
+				TIFR0 |= (1 << TOV0);
+			
+				/* Never send more than one bank size less one byte to the host at a time, so that we don't block
+				 * while a Zero Length Packet (ZLP) to terminate the transfer is sent if the host isn't listening */
+				uint8_t BytesToSend = MIN(BufferCount, (CDC_TXRX_EPSIZE - 1));
+
+				/* Read bytes from the USART receive buffer into the USB IN endpoint */
+				while (BytesToSend--)
 				{
-					break;
-				}
+					/* Try to send the next byte of data to the host, abort if there is an error without dequeuing */
+					if (CDC_Device_SendByte(&VirtualSerial_CDC_Interface,
+											RingBuffer_Peek(&USARTtoUSB_Buffer)) != ENDPOINT_READYWAIT_NoError)
+					{
+						break;
+					}
 
-				/* Dequeue the already sent byte from the buffer now we have confirmed that no transmission error occurred */
-				RingBuffer_Remove(&USARTtoUSB_Buffer);
+					/* Dequeue the already sent byte from the buffer now we have confirmed that no transmission error occurred */
+					RingBuffer_Remove(&USARTtoUSB_Buffer);
+				}
 			}
 		}