I am sorry to hear you are still experiencing this problem. However if the problem is in our Firefox extension we need to reproduce it locally in order to fix it. If your app is publicly accessible then please attach a copy of a test that demonstrates the issue so I can troubleshoot it directly. If it is not, please record a fiddler trace using FiddlerCap
and provide it to me so I can run the test against it. Basically with that trace I'll try to "simulate" your app in order to reproduce the problem. If you deem that information too sensitive for this forum, you can create a support ticket and attach it there.
the Telerik team