I have just managed to book 4 tickets online.
I don't know if it had anything to do with it, but I had been using Firefox since 8.50am and got no where. I switched to IE8 and after about 10 refreeshes it let me straight through with no problems. Good luck - I feel your pain.
This is so unfair, i want to get one of those exotic error messages. I'm extremely bored of the SERVER BUSY page. They could have put a pretty picture of the snow on there or something. FFS.
I'd be worried if people were actually booking tickets but as it is I guess there are still 2,000 available?!
Bloody computers. What's wrong with an old fashioned queue?!