We are working on an ASP.NET web application which features extensive use of ASP.NET AJAX, Google maps, and bespoke JavaScript. Everything is working 100% in all browsers except IE6.

In it, on most of our pages, the application will eventually hang, creating an Application Event to that effect. We have tried to identify what it causing this in the hope of resolving it, but are currently unable to do so. The "AjaxToolkit" application (which we're using quite a bit) seems to work fine in IE6, so we're thinking that it's more to do with our application than any of the frameworks or servers we're using.

Could anyone point me in the direction of any tools that might help us figure out exactly what is going on and sort this out?

All advice greatly appreciated. Many thanks...

Hi,

are you disposing of all your eventhandlers that you created? Cleanup in javascript/ASP.NET AJAX's necessary to take care of because you can get memory leaks and very slow performance. Especially in IE6. My first guess is that this is the case.

Grz, Kris. 

Hmm. It's actually more frustrating than that. Our issue, after lots of flaffing about with .axd extensions, server settings, etc actually lay in our stylesheet. We had some IE6 specific "expression"s in our CSS which, rather than making the site work and look right in IE6, actually caused it to barf.

Excrutiatingly frustrating, but there you go. CSS expressions can kill IE6. Hope this is useful to someone else.

Thanks for the information! How did you actually find out that it was these CSS expressions? Which tool did you use or was it rather like "we already try everything this is just the last stupid thing that we could look at before smashing the server..."?

Grz, Kris.
 

XIII:

Which tool did you use or was it rather like "we already try everything this is just the last stupid thing that we could look at before smashing the server..."?

Yup - something like that. The turning point was when I noticed that the same thing was happening when I took a static HTML cut of the page and tried to load that. It kind of ruled out anything happening on the server which had been our point of focus. So I started removing external file references (JavaScript, etc) and when I finally removed the CSS, the world came alive.

Talk about a pain in the ass! Hopefully, though, this will be of use to someone in the future.

When I look into it, CSS expressions (which were once considered a pretty clever way of getting around the inadequate CSS handling of IE6) actually cause it to hang in lots of environments. So I'd advise everyone to avoid them altogether. They're IE specific anyway, and IE7 is compliant enough that you don't need them. Sad thing is that statistics are still telling us IE6 is the most popular browser on the planet, so we can't disregard it just yet!

Cheers!

Just took me 3 days to discover the same thing!

Trouble is, I was getting caught up investigating WebResource.axd and Http compression thinking it was in there...!

What a pain..!

Cheers.