Yes I have opened the job up. It is under the 'Management' \Maintenance plans folder and when i open it I see that it is a 'Check database Integrity Task' for 'All system databases' with no other steps involved.

When I look at the job under the 'multi-server Jobs' folder I have checked that all the servers required to have this job applied are selected in the 'Target Servers' option.

I have noticed there is a Rebuild indexes job for the user databases which runs 15 mins before hand . If these jobs where to 'overlap' each other, could that be the cause of the problem?

Might it be worth redesigning the Maintenance plan so instead of 2 separate jobs, I create 1 job with 2 steps, the first being database integrity checks of the system db's then follow that on completion with the index rebuild job of the user db's ?

I was actually thinking about using Michelle Uffords' script to run the index rebuild operations anyway on a scheduled basis !!!