Mail accounts connection failed in Mountain Lion

I upgraded to Mountain Lion yesterday on my (mid 2010) Macbook Pro and everything seems to be great apart from the Mail app.

My mail accounts seem to constantly lose connection if I leave the Mac alone for a period of time, i.e I let it go to sleep, and then start using it again.

The connection failed is displayed next to each of my accounts (Gmail, couple of IMAP's and an exchange) and even though the connection doctor says the Internet connection is fine - attempting to take the accounts back online just does nothing and the accounts continue to be offline and not receiving mail.

Only way I can resolve it is to completely quit out of mail and re-launch it, then everything is fine again until I decide to let it sleep again...

Has anyone else been experiencing this at all? I've looked around but couldn't find anything. Not even sure where to start in trying to find the problem, as they simply don't connect, that's it.

EDIT: Though after posting I have noticed others are seeing the same issue:

https://discussions.apple.com/thread/4149792

Message was edited by: adam7351