I'm having the same issue, as well as a few others. I've let gav know so he can have a look.
What type of phone are you using? Maybe check and see if cookies are enabled?
If you're using an iPhone, there is a known issue since the iOS 6 update. It's being worked on, we hope to have it fixed by next week.
Not at the moment, no. There's an issue when using an iPad/ iPhone to access the chat part of the site, since the iOS 6 update. We're working on it, should be fixed this week. I'll keep you posted.