Generally you should include more information with your question if you like to get help. Others must get a clue about what happened.
I suppose you don't have any DSP effects enabled. If you have, tick them off. You could also download the latest soundcard drivers, install them and experiment with the options. What soundcard do you have? Are you using analog or digital output? Did you try other programs?
Paste also your System Info from the Help menu here. Like this:
Media Center Registered 10.0.161 -- C:\Soft\MJB\
Microsoft Windows XP 5.1 Service Pack 1 (Build 2600)
Intel Pentium 4 2859 MHz MMX / Memory: Total - 1048 MB, Free - 586 MB
Internet Explorer: 6.0.2800.1106 / ComCtl32.dll: 5.82 (xpsp1.020828-1920) / Shlwapi.dll: 6.00.2800.1552 / Shell32.dll: 6.00.2800.1556 (xpsp2_gdr.040517-1325) / wnaspi32.dll: Internal ASPI Layer
Ripping / Drive F: HL-DT-STRW/DVD GCC-4480B Mode:ModeSecure Type:Auto Speed:Max
Digital playback: Yes / Use YADB: Yes / Get cover art: No / Calc replay gain: No / Copy volume: 32767
Eject after ripping: No / Play sound after ripping: No
Burning / Drive F: HL-DT-ST RW/DVD GCC-4480B Addr: 1:0:0 Speed:10 MaxSpeed:48 BurnProof:Yes
Test mode: No / Eject after writing: Yes / Direct decoding: No / Write CD-Text: Yes
Use playback settings: No / Normalization: None