Comment 5 for bug 697210

Got it too.

[...]

Processing triggers for libc-bin ...
ldconfig deferred processing now taking place
Processing triggers for menu ...
Errors were encountered while processing:
 indicator-virtualbox
E: Sub-process /usr/bin/dpkg returned an error code (1)
A package failed to install. Trying to recover:
Setting up indicator-virtualbox (1.1.1~astrapi~natty1) ...
gtk-update-icon-cache: No theme index file.
gtk-update-icon-cache: No theme index file.
dpkg: error processing indicator-virtualbox (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 indicator-virtualbox

Using linux Mint Katya x64.