Not rendering for all passes

Sorry to bother you again but when  I render today i only get 2 passes instead of the usual 40? any ideas.

The first culprit to check might be the 6000 seconds limit set. That means it will stop after 100 minutes,

Try setting that to zero, so that it will run for the full 40 passes. It might take a while though, if it's a complex model.