Hey guys,
Just trying to fire up my audio interface recently and I'm encountering old issues I thought I had resolved. Anyways, I have my M-Audio Fast Track Pro hooked up to my PC and have my guitar running through it; speakers are hooked up directly to the audio interface. Anyways, I have the settings set to run through ASIO, I have the two Master's set to my interface and only my interface selected as the device. As soon as I get into the program though I get a message saying, "sample rate not supported by USB" or something to that effect. If I go back into settings, all my audio interface info is missing as options for device or master ins/outs. ASIO is still the selected driver mode so I'm not sure what's going on here...I had a similar issue before but it somehow almost resolved itself. I pretty much expected to just plug in and play but I have nothing registering within sonar so I'm at a loss here, any help is very much appreciated, thanks!

I used to own the same interface, The drivers were not the greatest. It would cut out and caused a very embarrassing moment at a dance concert when I was using it for playback. Anyhow One thing I learned was if you have any traces of Creative or asio4all drivers then you'll lose the drivers for the Fast track in a blink. But I gave it away as there was this issue with the buss power causing a hi pitched scream in the background. 
 
You might want to post a lot more about your set up as we have no clue what PC your using etc. 

How are your sample rate settings? Are the settings for SONAR and Fast Track the same, and is that rate supported by Fast Track in the bith depth mode you're using? What operating system do you have ? If Win7, does Fast Track have drivers for it? The online manual I found only mentioned Windows XP.

I have the sample rate set to 44.1 in both programs, running in Windows 7. I thought that my drivers were all up to date but I should probably double check again. Also, I'm not sure about your second question which was "is that rate supported by Fast Track in the bith depth mode you're using?" Not super sure what this means to be honest, pretty amateur in the home recording department. I thought about changing the sample rate to 96 in both to see if that helps, not sure what else I might try, thanks guys.

There is Windows 7 64 bit drivers for it as I used them for a short while. But somehow I'm thinking the Fast Track only worked at 48 for me ? I sure have a lot of old projects at that rate. 
don't go to 96 that will only make things worse for you.  
I remember to get the drivers they made you fill in a whole bunch of information every time you returned to the support page.  :( 

doclightXIX
 Also, I'm not sure about your second question which was "is that rate supported by Fast Track in the bith depth mode you're using?"Not super sure what this means to be honest, pretty amateur in the home recording department. I thought about changing the sample rate to 96 in both to see if that helps, not sure what else I might try, thanks guys.

Quickly reading the manual I downloaded I noticed that the supported number of channels and sample rates varies according to which bit rate you're using (16/24). Many interfaces have more limitations when you use higher or "unconventional" sample rates. Didn't go any deeper as I don't own a Fast Track