When I use Gearbox and/or Riffworks, both software packages do everything they are supposed to do with the exception of playback.  Neither program will play sound generated from the software through the Line Out jack to my amp (e.g. Metronome, Instant drummer, tracks, recorded riffs, etc.).  I can hear my guitar through the amp and I can use Gearbox to modify the sound, but I can't play anything back.  Likewise, Riffworks will record and operate correctly, but won't play back.

The strange thing is that I do hear all of these things play back through the Phones jack.  If I listen through headphones it sounds great, but if I plug the phones jack into my amp, it clips the signal and adds unwanted distortion.  If it wasn't for that, I would just use the phones jack as a workaround for the problem. 

Unless I am mistaken, this is not the intended behavior.  I should be able to hear these things in my amp connected to the line out.  FYI, the same is true for the "Windows" sounds (e.g. iTunes, Windows startup sounds, etc).  I can hear them through the phones jack, but not the line out.  Please help.  What is wrong?

I am using my POD X3 Live with Gearbox and Riffworks installed on a computer running MS Vista.  I have used the Line6 Monkey to ensure that all the latest versions of drivers and software have been downloaded.  The computer is a Gateway with Intell Quad Core Dual processors (2.33 GHz) and using 8.00 GB ram.