a lot of things can be changed to effect the communication:
+ Station addresses (PLC #2, PC #0)
+ Baudrates and protokolls
+ ASCII protocoll used at PLC
Switch the PLC to stop mode and try once more (this disables Freeport mode (ASCII) at the PLC interface.
the stations addresses for PLC and PC (must be different)
Try different protocolls at the PG (PPI, MPI, DP) with different baudrates.
Basically you communication works because you can connect to other S7-200 PLC. So there is something wrong with the settings.
Some funny guys change the PLC station address to 0 (via PLC program). If you do not change the Station address (default station adress is also 0) of the PG, then you can't communicate to this PLC.
Try the second PLC Interface when PLC is in STOP.
Hope this helps