Thanks for your response.

There was 3.2GB on the box- 2.5G allocated to SQL. The average avaliable mememory was less than 200mb across the day although we'd reduced the number of processes to a minimum- resulting in the above error with almost every query ran against it.

As an MI dept when SPID's hung for too long (hours) we'd kill the proces which would then go into roll back then we tended to reboot the box- this started happening weekly.

This solved the issue in most instances but ( as far as i understand) we were openeing ourseleves up for some sort of data corruption.

I think this finally caught up with us. To fix it I eneded up backing up the master DB. Touch wood this seems to have resolved the Locks.............although i wouldn't recommend managing your datawarehouses like this!