DavidG, can you do the following:
stop the collector service on the server
re-install the client on two of these client machines by using the systemhound.exe or calling the login script, etc, then send
hwinfo.log and
upload.dat from systemhound\logs on both machines
(not the server) to
support@systemhound.com with the URL to this thread.
restart the collector service
comparing the files from both will help us determine if its the same issue causing the freeze