17803 errors all over the place....

We have close to 400 SQL Server instances to manage. Within the last month we are starting to see 17803 errors at least once a week on completely different servers, different customers, different hardware, etc. We used to get one maybe every 6 months. SQL 2000, SP4 + .2187 hotfix rollup on most.

Anyone else seeing this? I'm wondering if something at the O/S level is the commonality (assuming there is one).