DWR: IE Page Refresh Very Slow

I am using DWR for developing a web-based chat application. Everything works great except one. This problem occurs only in IE. when i refresh the page (on which my chat application is running), the browser becomes very slow. The navigation icon on top right corner keeps on moving and status bar shows that 7 (or so...) items are remaining. But, here comes something more confusing- while IE is navigating like i just explained, if i send a message from a different browser to this particular user who has been stuck in with IE for some time, it suddenly stops its navigation and shows a Done status on the status bar. The message sent to this IE user, though, has not been received. This is noticeable. Though, sending a message to the IE user, escape him from a long continues navigation, he does not actually receive that message. After this, IE is in a good state and can send and receive messages without any problem.  
I am using Util's addFunctionCall for notifying clients about any messages sent to them.