Music gets louder and quieter (WMA VBR)

[etnpnys]

While playing songs that I ripped from CDs in Windows Media Player's Variable Bit Rate, they sound louder at times (higher bit rate times?) and quieter at times (lower bit rate times?).

Is this a codec issue? I don't know which one I'm using right now - but I can find out if absolutely necessary (away from HTPC right now). Do you guys know which codecs to avoid?

TV-Server Version:
MediaPortal Version: 0.2.2.0
MediaPortal Skin: Blue 2 Wide
Windows Version: Windows XP HE w/SP2
CPU Type: Intel Pentium D 3.0Ghz
HDD: Toshiba 160GB
Memory: 1GB DDR2
Motherboard: Intel Express 945 DGCZLR
Motherboard Chipset: 945GCZLR
Motherboard Bios:
Video Card: nVidia GeForce 6600
Video Card Driver: Always current
Sound Card: Integrated Sigmatel Sound
Sound Card AC3: Optical
Sound Card Driver: Always current
1. TV Card:
1. TV Card Type:
1. TV Card Driver:
2. TV Card:
2. TV Card Type:
2. TV Card Driver:
3. TV Card:
3. TV Card Type:
3. TV Card Driver:
4. TV Card:
4. TV Card Type:
4. TV Card Driver:
MPEG2 Video Codec:
MPEG2 Audio Codec:
Satelite/CableTV Provider:
HTPC Case: Evercase ECE1341
Cooling: Thermaltake BTX Fan
Power Supply:
Remote: Logitech S510 Keyboard & Mouse
TV: Westinghouse 32" LCD
TV - HTPC Connection: VGA