I recently installed the Release Preview of Windows 8 in a virtual machine. Some apps do not work. When I open them (by clicking on their tile in the start screen) I see a splash screen and nothing else happens. Sometimes the app crashes after 30 seconds, sometimes it just keeps on loading.

A good example is the "Map"-App from Windows 8 or the app "Cookbook" by Bewise. I installed Cookbook and when I had a look at the task manager I saw that it was the 32bit version running, but I have an x64 Windows 8... Could this be a problem? Shouldn't the Windows Store download the correct version?

This is the setup of my virtual machine:

• Windows 8 Release Preview x64
• Oracle VirtualBox
• 4 of 8 cores from host system
• 8 of 16 GB RAM from the host system
• 256 MB graphics memory
• guest additions installed
• resolution 1920 x 1080

Do you need further information? Unfortunately there is no error message... I just see the start screen of the app with its logo and it keeps loading, but nothing happens.
Other Apps (like Mail, Video, Social, etc.) work fine.