I'm writing a class driver for a USB device under Neutrino 6.4.0.

In certain modes this device may create data packets as large as 24576 bytes (i.e. 3 * 8192 bytes) which are transferred
 using bulk I/O requests.

When the class driver requests a bulk transfer of this size, the usb stack makes the completion callback into the class 
driver, which I handle and then, the request is now technically complete, I delete the URB and the buffer associated 
with the request. But then, mysteriously, the usb stack makes two more completion callbacks into the driver, passing me 
the address of the URB that I have just deleted. Any further activity with this USB device causes io-usb to crash (as it
 has apparently walk over its internal memory). At this point I can't simply restart io-usb -- it appears to just hang. 
I have to reboot the system.

The next largest packet size that the device will generate is 12288 bytes (i.e. 3 * 4096 bytes). I can transfer packets 
of this size from the device all day long with no problem.

Any ideas? Does io-usb have an artificial upper limit on the size supported for I/O requests?

Thanks
Dan