I have been getting this strange problem for quite a while.

Often when I print, the document will fail, there is a generic error with no info in the printer queue... and the only fix I've found is to unplug the USB for a second, then when I plug it back in it prints (does the same when you reboot). There is no error in the eventlog either.

It does this on onboard usb, on a usb PCI card, it's winXP pro...

could just be the usb cord itself...

Are you printing a heavy file ?
I have experience this in my office network printer when I send a heavy file the file takes a long time to print and even to be displayed in the print queue.
Only when the data gets into the print buffer in the print you could see the print info otherwise no.
Print a file and wait for some time and then conclude whether other parts might be faulty.

USB can be a strange bird and a bit flighty, if you will, depending on whether we've followed the installation instructions of the device in question.

We've pretty much grown up with the routine of, install the hardware then the drivers/software...

USB routinely asks us to install the drivers/software and then the hardware. If this is the case with your printer, I would suggest pulling the plug on the printer, and removing the printer in SAFEMODE. Look for any duplicate instances that might be found...if any are found, remove "ALL" instances.

Reboot, and follow the installation instructions (as mentioned, I suspect the drivers are to be loaded first), with the printer added afterwards.

One additional thought, to clean the slate so to speak, would be to also remove the USB controller in SAFEMODE. Upon reboot, Windows will locate and reinstall the drivers...might possibly be a hiccup in there also...

ill give it a shot...