Most likely that's what causes your problem (using original Oracle VB instead of Debian adapted VB).
Yes, but I find no way in aptosid install virtualbox from Repositories.
In synaptic I find:
virtuabox 4.3.14
virtualbox-guest-additions-iso
virtualbox-guest-dkms
virtualbox-guest-utils
virtualbox-guest-x11
which package should installed in Host and in Guest?
I have now installed VBoxGuestAdditions-4.3.14 from
https://www.virtualbox.org/ticket/12941It works also under siduction-December for gnome-session, but
only Shared Folder are successful.
Under siduction-Firestarter works in gnome-session and KDE-session, but without any effects.
with regards
Ch. Hanisch