I bought a UX1 used off ebay, and everything works great, the recording is good and playback is nice, but the only thing i am having a problem with is opening other programs while the UX1 is plugged in. i cant do anything with it plugged in, even if gearbox isnt open. but once i unplug it my computer runs fine, but with it plugged in it just sits there and doesnt do anything. and my computer isnt slow, its about 2 years old, with a 2.5 GHZ processer with 320 MB harddrive, but it does have Vista. Anyone have a suggestion?
Sounds like a driver conflict.
Search the Line 6 forums, I'm sure someone has run into this in the past.

I've had an older UX1 years ago when Vista was new and had a crapload of blue screen errors each day........ended up selling it and going with M-Audio.

These days I've got a PreSonus FP10 but they don't have any idea when W7 drivers will be out nor will they say if they are even working on them......quite lame.
Make sure usb ports are 2.0.

Make sure in device manager USB host controller does not have problems. Try reinstall or updating it.

try another usb port.

Try in another computer.
make sure you installed the driver for the ASIO UX1 and that you're actually using that "soundcard", and not your pc's line in.