SQL Server client-side trace

Microsoft KB article 929728 describes a situation that can occur in SQL Server 2000 and 2005 when you use SQL Profiler to perform a client-side trace of the events in the instance.

Had just this situation today, users had been erporting the instance as performing below it's best for several days. Noticed that many sessions were showing a LATCH_EX wait on resource MISC (42DA8A08). That exactly fits with KB 929278 and we eventually tracked down the trace to having been started from another server, running a well known monitoring tool.

Moral of this story - don't start jobs and leave them unfinished.

PS:
It is also possible that LATCH_EX waits on resource MISC might be due to I/O problems but there is precious little documentation about the MISC wait resource to confirm or refute this.