Firebird/linux AMD64 (access method), version "LI-V2.5.0.26074 Firebird 2.5"

Had this website / db running on another machine without problem (oldest and next transactions tracking along).

Used some scripts for db updates and oldest transaction seemed to be stuck. I did a sweep and various other gfix tricks and nothing seemed to work. Mend reports no problems now, though had one error initially.

I have now done a succesful back up / restore - but all the following data points are stuck except next transaction.

Oldest transaction 331
Oldest active 2
Oldest snapshot 2
Next transaction 458

Any thoughts on how to identify the problem and fix this?

If it looks serious I could go back to a previous version of the DB, though would prefer not to do this and certainly not delay the decision.

Thanks for any help