How to fix bug in Categories Management

Hi guys,

I found this bug in latest version of WP (trunk #4455) but all previous trunks have this bug too… Want to ask somebody how to fix it…

BUG:
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!
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.

Maybe somebody knows how to fix it?

Thanks,
Dan