For those that think Microsoft Connect is useless
A while back I reported both through my weblog and Microsoft Connect what I thought was a serious flaw in the WPF validation infrastructure for ValidationRule and Binding. The issue, in short was:
The validation check is invoked during any attempt to update the underlying data ... before a value converter is called (if present)...
Take special note that this was not some undocumented, strange behavior, but rather something that was explicitly explained on MSDN where the validation process was explained...
Read full article