Windows XP Playback Problems/Solutions

[Cerebra]

I have installed the new Nimo Codec pack along with DivX 3.11Alpha, 4x and 5x, however Windows Media Player 8 plays the sound but not the video. However, there is no problems with my codecs as when i load the movie into Media Player 6.4 (C:\Program Files\Windows Media Player\mplayer2.exe - Also produces faster refresh rate on older graphics cards) the movie plays perfectly, but does not produce as smooth quality as it would in MP-8 plus MP-6.4 does not have features such as TruBass, WOW Effect, Graphic Equalizers and Video Settings. Is there any way i can get MP-8 to play these movies? (without having to install MP-7)