MBATR: OK you have the six speed manual and on a shift "sometimes" there is a lurch as if the engine slows down. Offhand I can think of two things that could do that:
1) momentary loss of fuel pressure
2) momentary loss of Throttle Position Sensor (TPS) signal (assuming you back off the accelerator during a shift. (keep in mind the Crossfire is "Fly By wire" and there is no mechanical linkage to the gas pedal, just two Hall effect sensors).
Both are going to require instrumentation to determine, otherwise are just throwing money at it., The first a fuel pressure gauge, the second a scanner like Torque Pro, monitored when happening.