Bug#445146: sculp mode not working

[Benjamin Green]

Confirmed under Debian Unstable AMD64.
There's no error output I could see but as an immediate solution I found out
that the official 32-bit build for linux from blender.org works fine.
All 64-bit builds I've run including my own subversion checkouts have the
same problem, also had someone else check under a different 64-bit distro
where the problem wasn't present.