got a link to the printer. Ctc used to make a dual extruder, not available any more so i'm not sure exactly what machine and model you have.
Looks like you have repetier firmware - so that's good :-)

Also sounds like you have a filament sensor.

Hmm, quick look on ebay - looks like they're making the replicator clones again.
So is yours a 'bizer' model ?