Strange tabbing problem

Question

I have a strange problem with an asp.net web page, I have a number of text boxes on the page but whenever I tab out of any them the focus goes to the address bar and from there I can't tab to anywhere on the page. The text boxes are contained within a tab container asp.net ajax control and I have some modal pop up extenders but other than that its a pretty standard page. Has anyone come across this before?

Answer 1

Found the answer, I had a modal pop up extender control always showing but hidden in an update progress control (So when the progress control is shown the modal pop up extender is shown as well) ....bad idea