If you have read of the BOINC 6.10.32 message thread (in Number Crunching) you will notice there is a bit in there regarding an update to the server software.
The "suspend computation" feature requires a server-side change to control it.
Just noticed its there under BOINC computing prefs. However the project resource share doesn't accept zero which I understand is how one triggers the backup project "feature"[/edit]
Also I think Richard asked this before, there are two sets of use cpu/gpu questions under prefs. I thought one pair of them were removed.