I use Mandriva Linux 2008.1 here, and the version of Virtual Box included with my current Mandriva release is VirtualBox-1.5.6. THis version worked well for me here, but I saw that Sun has a newer version available (VirtualBox-2.0.2). I'm a computer tinkerer. I had no choice to get the latest version from Sun and give it a spin. TO keep this short enough so you will get through it without giving up, I find that I prefer the newer release (VirtualBox-2.0.2).
I downloaded VirtualBox from the
Sun WEB site, then uninstalled the version from Mandriva, and finally installed the rpm I got from Sun.
Please take note that I was not having any trouble before switching to the newer version, but it is possible that installing the latest version from Sun will correct whatever went wrong. I do not normally suggest installing software from sources other than what has been packaged for your distribution (Mandriva packages for Mandriva users, Suse pacages for Suse users, etc.) but Sun has packaged Virtual Box for several distributions including Mandriva, Fedora, OpenSuse as well as several others. For this reason I consider the packages to be more likely to work correctly with your distribution (I had to use the 64bit package for all distributions since I use Mandriva x86-64 o my AMD dual-core powered system and still obtained excellent results).
HTH,