Roger Wilco Problems

Dear Members, I am, currently runnig Fs2000,due to pc low resources.MY PC consists of PIII 800,256 MB ram and a GEforce2 Mx400 Video Card,and with a Yamaha Audio Card (OPLSA).I am having problems,with RW.When I start RW only and do the test ( Wav sound) I hear myself very good,And when I use Rw with my FS2000 and make the same tests,I am hearing an echo.I tried as well direct sound but it was all for nithing ( altough i noticed that the recording device has like this ( emulated).One thing the for any reason I used Wav format the Playback device and recording device had this (emulated) the sound came good in fs2000.Could someone please help me as I am in a big panic! Should I change my sound card or Re-install fs2000? I just can't continue flying like this...as the other ATC (IVAO or VATSIM) ar complaining about the echo that is coming..(ex if i say roger another roger will be heard )I hope that you will help me Guys...Regards :-zhelp