EM12c false alarms for blocking locks

Lately EM12c has been alarming me with false alarms on the Blocking Session Count metric. It's collecting the metric every minute and even though I keep cranking up the "Number of Occurrences" value from 1, 2, 3, and 5, it still keeps alarming a few times per day (and night!).

The target DB has never had a locking issue. And when I investigate the new block, it's gone. The offending processes are everything from LGWR, PQs, and regular user sessions. It seems like it's alarming for some "benign" lock (e.g. shared) and ignoring the number of occurrences. It's also only started since I installed the BP1 EM12c patch, although not immediately after the install. I just upgraded the target DB from 10.1.0.5 to 11.2.0.3 (yay!), and there's no change in the pattern.

Anyone else seeing this? I've got too many SRs open already... :)

TIA! Rich

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