CPU Usage in Firefox when closing or moving away from a page

CPU Usage in Firefox when closing or moving away from a page


I have listings page that uses jquery to attach simple click actions
to each item.
Each item has a delete button, which when clicked shows a confirm/
cancel dialog.
When the page shows a large number of listings (full view on some
lists shows between 1000 and 2000), it loads and works fine (after a
brief CPU blitz) but when the user tries to close the page or clicks
any link, CPU rises dramatically and Firefox locks up. Eventually the
'this script is taking too long' dialog appears - and cites a few
different jquery lines each time.
It seems to work ok in opera and safari, though my main development
platform is Firefox with Firebug, so I've not tested the others so
extensively.
What part of jquery is running when the browser leaves a page? Any
thoughts?
Thanks,
Joe