If a user navigates away from a page while that page has a pending asynchronous ajax request that request will most likely hang and just remain sitting there hogging one of the (normally two) available per-domain connections for a few minutes. If more requests get stuck and all available connections are exhausted then the browser may appear hung. As far as I can tell this seems to apply only to IE (6-8) and only to asynchronous ajax.
The only workaround I have found is to keep track of all outstanding requests and abort() them "onunload".
Has anyone else banged his head against this one and would like to comment?
Thx
D