You could try using WPE Pro to discard the converation close event.
Here's a tutorial on how to use WPE Pro and where to download it...
http://www.phuzion.com/?p=tutorials/cheating/packet
Have fun, and if you make a filter, post it here, it might get useful...
Note: Some antivirus programs say that there is a virus with WPE Pro, but there actually isn't one...