The fast track line is notorious for the wide variety of problems that come with using them.
I have a fast track pro and I've definitely had some issues with mine.
First of all, what exactly are you trying to record? I'm guessing guitar?
A few things that might help:
Check that the track in protools is input/record enabled - if you don't set your audio track up so that its record and input enabled it won't record anything. I have definitely made this mistake before haha.
Go into your ProTools preferences, check that the fasttrack is set as the audio input source.
Go to the website, download the latest drivers, update everything, then turn off any inputs/outputs you aren't using.
I think one of those will probably solve the problem, but if they don't, bring up the manual and start reading any and all relevant information.