My canon flash will not fire?

I have a Canon XT DSLR. It has worked perfectly until christmas morning. When I try to take a picture, the flash will pop up, but it never fires. The display inside the view finder will show "busy". After a few seconds, it will eventually take the picture without the flash. I contacted canon, they said send it in, they will look at, but oh, by the way, it's out of warranty, so make sure you send in an arm and a leg along with it to pay for it. I have tried removing the battery, as well as the memory battery, as well as changing settings. Nothing worked. Has anyone else experienced anything like this?