@Paul Newell - I believe what OvercautiousAdmin is referring to is the KB article on the subject: http://support.microsoft.com/kb/2822208
I'd like to make one thing clear though: while there have been customers impacted by this (a bad thing) - this problem is very far from being super-frequent (a good thing). We have done a lot of work internally to understand the impact of this issue and it is not widespread by any stretch. Not every customer using voice mail systems and/or applications that attach PDF files will be impacted by this. It took us over a week of work internally, pretty much around the clock (as we have support centers around the world) to reproduce this problem in the first place, even though we were specifically targeting such messages.
What I am trying to say is - we realize this is a problem, hence the KB article. But if this was a wide and frequent problem, you'd read about it here on the blog as an announcement of some sort. It is not.