Ok, to answer my own question after a fashion:
Switching FIPS modes requires exit/restart of Firefox. Seems they are
"talking" about adding a prompt to warn users enabling or disabling FIPS
that they must restart for proper operation.
Following this procedure, I was able to renable FIPS & still have Update
check work properly. I can only guess that with FIPS on when the 1.07
update was applied had some effect (preventing further update checks)
and that only went away after disabling FIPS, restarting, enabling FIPS,
restarting.
Only reason I found this was I tried to enable FIPS in Thunderbird and
hit the same wall trying to update my extensions. So I looked further on
BugZilla for FIPS hitting this item:
https://bugzilla.mozilla.org/show_bug.cgi?id=148305
warpmedia wrote:
Just did the 1.0.7 upgrade and suddenly my extensions can't find their
update servers using Extensions->Update.
Worse, open Options->Advanced->Software Update->Check Now and I get
blank window saying there's updates but nothing listed.
Turn off FIPS in Options->Advanced->Manage Security Devices->Device
Manager, and then all is well again??? No problems with FIPS on before
loading the 1.0.7 update.
Do I open a bug report or is this expected? Ideas?