Well, I have made a filter for WPE Pro that will do this, however, there are some problems...
Check this reply about the filter:
Mike's reply to Patchou, Feature Request
Check this reply about what can happen when you use the filter:
Mike's reply to Patchou, Feature Request
You can download WPE Pro here:
http://nimmy-online.com/jj2networkfilter/WpePro.zip (Some antivirus programs, say that it contains a virus, but this is not really true, so you should put all the files into your antivirus' exeption list.)
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