Canon Scanner was working now its not please help

Hi There

I brought this scanner (CanoScan N670U) a few months ago and it was working perfectly up until about 3 or 4 weeks ago.

My operating system is Windows XP.

I have been using the CanoScan Toolbox, and suddenly this stopped working, saying:

"Unable to open TWAIN source Please check connection Then re-start Toolbox"

I have tried a couple of other programs, but they don't work either, I have tried unstalling the scanner and software and that didn't work. I have downloaded a new TWAIN.dll file from the net and replaced the one in the WINDOWS folder, and that didn't do anything.

Also Cheap Youtube Views I can see this Scanner in my device manager saying thats fine and properly installed, and another thing, when I plug it in, it makes a little noise to show that its been turned on and has started up.

Does anyone have any other suggestions??

Thanks

Jackie