In next weeks batch of updates from Microsoft there are two updates for Windows Media Center. One update is for TV Feature Pack and one for the release version of Media Center, watch out for them appearing on Windows Update on Tuesday. More details on Microsoft support page

Thanks to Richard and Scott for the tip

Cumulative Update for Media Center TVPack for Windows Vista (KB956147)
Locale: All
Deployment: Recommended/Automatic Updates, WSUS, and Catalog
Classification: Updates, Non-Security
Target platforms: Windows Vista
Approximate file sizes:

• Windows Vista update: ~ 2565KB

• Windows Vista x64 update: ~ 3340KB

Description:
Install this update to resolve issues with Media Center for Windows Vista. For a complete listing of the issues that are included in this cumulative update, see Microsoft Knowledge Base article 956147. After you install this item, you may have to restart your computer. This update is provided to you and licensed under the Windows Vista License Terms.

Cumulative Update for Media Center for Windows Vista (KB955519)
Locale: All
Deployment: Recommended/Automatic Updates, WSUS, and Catalog
Classification: Updates, Non-Security Supersedes: KB47172, KB932818, KB941229, KB935652, and KB950126 on Windows Vista
Target platforms: Windows Vista
Approximate file sizes:

•Windows Vista update: ~ 12122KB

•Windows Vista x64 update: ~ 13384KB

Description:
Install this update to resolve issues with Media Center for Windows Vista. For complete listing of issues included in this cumulative update, see Microsoft Knowledge Base article 955519. After you install this item, you may have to restart your computer. This update is provided to you and licensed under the Windows Vista License Terms.