Considering the OP wanted the thread locked I'd suggest he either fixed the issue or burnt the car, Rather inconsiderate to not update if it was fixed and what the issue was either.
But in answer to your question, yes the transmission has a filter inside the sump.
Crap/old fluid can cause shifting issues (more likely to cause poor shifts or slippage) however be ware that the shift point is determined by load Vs RPM and load is based on the TPS. Once you get above a certain throttle setting the engine will rev out to max rpm before up shifting.