Ah ha. Just tried it on Firefox (after having just downloaded it) and I couldn't access it from there either...
...
however it did tell me why - it said the security certificate would not be valid until some date in 2007 and that my computer said it was Febuary 2006.
Reset the date and now everything is fine. Thanks guys.
So - next question - what little gremlin snuck in and changed the date on my laptop!
