Oh, it's a linux issue alright. If your num- and capslock are flashing, it means your machine is having a kernel panic. Since it's happening when using VB, it's kernel module is not working properly. Try to debug as much as you can, look at log files etc. to see what is going on. When you know, or need some additional help

, you can file a bug report in the
Bugtracker. Be as specific as possible, with exact settings and all. You need a separate account for the system though.