Bought a fastrack - didn't come with software but I use Garageband, Guitar Rig, Amplitube, etc... I was plugging directly in with an 1/8" adapter into my input on my G4 - sounds sweet. Now with the Fastrack (I've checked all settings in "SOUND" and "MIDI") I get only clean guitar from all apps? Tried plugging into my speakers and headphones tried different settings but all I get is "clean" - what am I doing wrong?

Clean is nice but I like down and dirty too

NO crunch at all - no matter how I set it up or how I turn the knobs - without it I get the Marshall sound - with it - sounds like a clean clean guitar - no crunch in Guitar Rig software or Amplitube - no crunch in GB either - disconnected it and set back up with built-in inputs and outputs - I have crunch?? is it broken or am I a dummy?

You're probably getting distortion with your guitar through your computers input. The way you are hearing your guitar through your interface is probably the way it's supposed to sound. If you like the distortion you get through your computer's input I would use that instead. It's either that or you need to change a setting on your fast track to hear playback from your audio apps and not just input signal from the fast track.

the distortion is built-in in GB, Guitar Rig, etc... FUZZ, Big Stack Sound, Etc. In GB there are lots of AMPS with disortion available but all I hear is clean when using them with the Fastrack

Sounds to me like the sound coming from your Fastrack is just the guitar going into the box and back out again... i.e. not going near your processing software.

Things to check: guitar into Fastrack, Fastrack into Mac. Then, in your audio preferences (in the System Preferences on your Mac) make sure that your audio input AND output is set to use the Fastrack. You should also check this setting in GB too, under the Audio preferences...

See... the audio needs to pass from guitar to interface to mac to software and back out to interface otherwise you're only hearing the sound at the interface... make sense?