False positive, how to set signature exclusion.

How do I know which signature to exclude?

 

I'm getting a false positive on a file... I know for a fact that it's clean.  I'd like to add this signature to exclusions because this file gets moved around some times and I don't want to have to add it to file exclusions every time I move it.  Here's the detection log.

(I removed the file name)

 

c:\documents and settings\*******\desktop\*****.dll
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On computer as of
6/25/2010 at 1:56:57 PM
Last Used:
6/25/2010 at 1:58:57 PM
Startup Item: No
Launched: No
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Many Users
Hundreds of users in the Norton Community have used this file.
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High
This file risk is high.
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Threat Details
Programs that infect other programs, files, or areas of a computer by inserting themselves or attaching themselves to that medium.
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Origin

Downloaded from  Not Available
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URL Not Available
UNTESTED

Source
********.dll
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File Actions
File: c:\documents and settings\*******\desktop\*********.dll
Removed
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File Thumbprint:
Not Available
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