I had this trouble too, I brought up the Windows task manager and killed off a few programs. I'm not sure exactly which program was the culprit, but I stopped any and all iPod related programs, and TVersity. That did the trick. I would think any program running that relies on a usb port would be fair game to try ending.
That sounds like a problem I had with a customers mx-810. If it's the same problem it's a driver issue. I think I may have had the same issue with the 880, but I cannot remember.
I received these instructions from URC, change 810 to 880 and it should work for you.
Open the editor and plug the MX-810 into your PC. Now, right click on My Computer and select Manage From your device manager, look for an unknown device (this is usually accompanied by a question mark or exclamation point). Right click on it and select update driver. After that select the option for Install from a list or specific location. Now navigate to this folder:
My Computer/Local Disk (C/Program Files/Universal Remote Control Inc./MX-810/Drivers/(Your Operating System)/x86
This will update the URC USB SYNC FW1 driver.
who ever said money can't buy love never bought a puppy.