We have a wee problem with some exchange 5.5 servers running a KCC every 10 minutes. This causes dsamain to hog all the processor time for a minute or so, slowing the system big time. It thinks it has picked up a change but then finds nothing. The systems having this problem are ones that have been upgraded, i.e. we have moved exchange on to the new server, but obviously with the same name etc, etc. Any ideas??