keyplyr - 7:59 am on Jun 9, 2011 (gmt 0)
Not an error. I just quickly grabbed it out of context so I could post an example for the OP. But even if used stand alone, some unix/apache server configs may treat the superfluous [OR] as an error, mine would not.
As for blocking blank referrers, too many legit users do this nowadays for my needs. Stock IE offers this feature as do several FF add-ons.