spurious log entries, skipping

My spam log files (not verbose) are filling-up with lines such as

> procmail: Skipped "OB:"
> procmail: Skipped "O:"
Every arriving mail generates a couple of hundred of these as it runs 
through every test
Any ideas on how to stop this?

Andy Mac
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FOCUS Internet Services
Web Design, Hosting, Internet Custom Applications
reg office : 62 rue de Mersch
L-8181 KOPSTAL
Luxembourg
tel. (+352) 305 197
fax (+352) 305 188
GSM (+352) 021 246 532
www.focus-services.com