Anyone seen this after SP4?

Executing a full database process at the end of an update, the cubes appear
to have updated and the commit has taken place but Analysis Services hangs
completely. Further updates hang, cubes not available to client tools and
service doesn't respond to a restart - the only way out is a reboot.

After reboot cubes are there and have been updated but for some reason the
job didn't finish off properly.

Any Ideas?