Got a weird one.... anyone else experienced it?

Went to exchange a dongle in a clients hired catalyst - reason being they had a V4 dongle due to availability - but were only running V3. So it was due to be swapped when V3 dongle was available.

Heres what happened:
Shutdown V3 mac in question
Opened up mac
swapped V4 dongle for V3 dongle
closed mac
re-started mac
catalst started (autostart)

everything (seemed) ok - correct 'cat settings' file - correct patch, cat name, serial controls, file ;locations etc....

However, when restarted didnt notice that the Sync ID's weren't correct......(aparently)
The Sync IDs were either not present or incorrect. - despite no change to the cat settings file on my part - or even going near the folder......

Has anyone noticed this problem before?
Is it possible for sync ID's to disapear after swapping dongles but all other setting remeain the same?
Syn ID;s didnt show up in any 'pre-show' checks due to no cues that used 'sync id' to check it.... so didnt notice the problem....
Essentially though - if there was only ONE cat settings - no copies etc... why would all the settings be correct except for the Sync ID's, when the system was restarted?
Anyone got any ideas?

Am I loosing it? (no comments thankx.....)

S