Audio input/output device types not compatible with Jack Detection on HD Audio cards may have a blank volume level control page in the Sound configuration window after an upgrade to Vista SP1
Consider the following scenario. You install or upgrade to Vista SP1 on a system with an HD Audio card. You open Sound from Control Panel, and click on any Playback or Recording device listed. You then click the Properties button, and navigate to the Levels tab.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB959463.