On systems with more than 3 GB of memory, with the awe enabled sp_configure option, SQL Server may report latch timeout warnings in the error log as a result of the removal of old plans from the cache. The error message may also display:
2001-06-04 17:10:35.55 spid106 WARNING: EC 59218090, 17 waited 7500 sec. on latch 44898144. Not a BUF latch.
See the Microsoft Knowledge Base article: Buffer Latch Timeouts or Server Sluggishness Occurs When You Remove Procedures From Cache.
http://support.microsoft.com/kb/309093/
