FS2002 - problems again!

hello!my headache is at top!I have an Athlon 1700 with a good 3d card Hercules 3500 64 mb.I decided to install more RAM since the 128 MB seemed to be not completely sufficient to support the FS2002 capabilities with all the software settings display ( hardware, aircraft, scenery) at maximum levels.I bought new RAM (further 256 mb) and now, at 384 MB the situation is as follows : the FS2002 runs very fast, the spot view is superb without any stop, the virtual panel works very well with external sceneries running smoothly..BUT : flying it from the normal panel view, the frame rate falls down at impossible levels.. even a correct landing became impossible... The trouble occours with the above said selections at top BUT also with selections at minimum..I noted that the frame rate in the PANEL view is now normal ONLY when the hardware acceleration is unselected ! What can I do? What close relationship does exist between RAM and 3D Video card ? May be necessary to re-install FS2002 ? Help please! Kikko