Just to emphasise it is really rare. I know a few (unlucky) guys here have experienced it (and I'm sorry about that
), but the game went through four separate QA departments (Eidos, Crystal D, Buzz Monkey and Nintendo) and the bug wasn't recreated. We've only had seven calls to Customer Services about it in the UK, and using a previous save or one of those that Eidos has provided will fix the issue.
If for some reason it doesn't please send me a PM so we can help.