I've never noticed that before but hopefully it is a normal part of the IDS process after it gets its rule updates or something.  Here are some snippets from my logs as well.  I'm at firmware 13.28 and Prevention/Balanced mode. 
 

					
				
			
			
				
	Adam R MS | CISSP, CISM, VCP, MCITP, CCNP, ITILv3, CMNO
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