When I delete category, software initiates ajax request to the server, then delete item from the table by ajax response, correct? If so, after it I get JavaScript? error: Object doesn't support this property or method.
I use IE7 and thought that this bug in JavaScript? with new IE release, then I checked it to Firefox and got this JavaScript? error after deleting category (copied from JavaScript? console):
$(id) has no properties
http://my.domain.com/wp-includes/js/list-manipulation-js.php?ver=4187
Also, as I can see sometimes when I receive this error I also get this alert box (mostly Firefox):
Are you sure you want to navigate away from this page?
Slow down, I'm still sending your data[[br]]
Press OK to continue, or Cancel to stay on the current page.
This bug presents in IE all time, but in firefox only for first deleted item. Then I do not see any errors, deleting goes well.