The main problem here, is shared folder... it often fails.
Host: Windows XP, VBox 3.2.0-BETA2
1. Shared Folders: Vista/7 guests only. (32/64-bit) -- happens when you run normal user account. Works with Administrator account.
This bug existed in 3.1.0 too, but not fixed.
Many executables refuse to run fom Shared Folders:
http://www.virtualbox.org/ticket/5732
2. Clipboard sharing (Vista/32 guest)