Norton 2004 Product Line is A LOT more sensitive to this due to changes that Windows XP Service Pack 2 makes.  The WMI Patch that it installs for compatability may improve it a bit, but the problem is still MUCH more common on the 2004 product line.
If you're using a 2005 product, chances are Norton just malfunctioned once or twice or a program tried modifying a Norton file.
Norton is good software.  But all software has bugs 

, so you can understand that, cant you Patchou?  Renew your license. </symantec whore>