Waittype of resource_semaphore indicates a wait on memory grant. Here is an article that may be related.
http://support.microsoft.com/?id=309256
If there were SPIDs waiting on Resource_Semaphore, this is a symptom
indicating that there is some other query/queries which are taking too much memory and not releasing quickly enough.
Yih-Yoon Lee
lee@yihyoon.com
Yih-Yoon Lee
lee@yihyoon.com