It seemes, the version of virtual box, you can get over implemented repositories, does'nt work a 100% in all funktions.
... last working of this version @ ubuntu 10.10...
It should be possible to implement virtual box from oracle's web page incl. the key, by implemented repositories from before.
If not liked, it might be usefull to implement tips / links into standart browser, braught by system from beginning
Regards.

Please excuse my bad English

seems this is more *buntu specific and would be more relevant in their forums

you should also specify what functionality isn't there

I used the ubuntu-version to discribe an era where it functioned.
it is an relevant problem to debian / kde
used system; back|track 5 r2
in repositories: (all relevant files of virtual box) highest version-numbers found 3.2.8 -> sometimes 4.0.0
in this versions the software(-installer) for using common folders does'nt function.
This might depent on changeing structures in debian & ubuntu after named era