Secure Forum Software

Not sure if this is the right place to post this but it cant hurt.
Ok I was just wondering with regards to forum software, what is the most secure one out there.
I used to run a PHPBB forum on my site and I liked it a lot, modded it, kept up with all the patches, which was a pain in the ass cause at that time there were a lot of worms going around, but then my webhost decided to disable PHPBB cause of the 'security risk'.
lets just say I was pissed off.
But anyway I now a friend of mine wants to set up another forum with me, he is a big vBulletin fan and is willing to shell out money for licences and all the rest.
Is vBulletin really better or more secure than PHPBB, is it worth the money and most of all, whats a good secure hosting service for hosting forums?

 

I transferred my forum to vbulletin, too.
I was using SMF, and I wish I still use it. SMF is the most secure and one of the best supported forum software around.