Hello, Mageia 3 is so far working correctly in Virtual Box 4.2.12 with the display and sound working right out of the box on my AMD 6870 video and Core-i5 660 with Intel chipset motherboard. The only thing not working was a permissions denied error accessing my 2 Windows 7 host partitions. To solve this easily do the following:
1. Go to the Mageia Control Center
2. In the Control Center choose System, Manage Users on System
3. double click on your {user name}
4. In the Edit Group/Users window select the Groups tab.
5. Scroll down to near the bottom and check the vboxsf group
6. Click Ok.
7. Shut down and restart Mageia 3 in VBox.
You can now go to /root/media and double click on the host drives you set up as shares when you installed Mageia 3 in Virtual Box. You can then create a symbilic link to them in your home directory for easy access.