This is a word of warning for anybody developing with the AJAX Control Toolkit using IE7. I deployed my code onto a test server today and started to run through it before unleashing it to the test team. The company I am developing for use IE6 across their estate but I had been developing and testing using IE7. Its only when I clicked through the app using IE6 I discovered that partial page updates no longer work. After a lot of searching on the internet I discovered this is a bug that has yet to be fixed with the CollapsiblePanelExtender within IE6. The page is correctly performing a partial page update but the browser decides to redraw the whole page anyway.. very frustrating!

Does anybody know of a workaround for this? Or an alternative CollapsiblePanel control?