netmeg - 7:16 pm on Jul 31, 2012 (gmt 0)
Nope, not me. For the last 7 days, "unmatched requests" were only .018263 of my total requests.
I have different ad units for text and image (which I rotate on my own basis) and I only have the AdWords network enabled, for whatever that's worth.
Oh - one thing I noticed that when I took link units off a particular site, my unmatched ad requests all but disappeared. Are you running link units?