On: Post-mortem on New Relic's Move to Ruby 1.9

We had the same suspicion but only one customer had observed it repeatably in the wild. We turned out to be customer number two. :) If you're running 1.9, definitely get agent 3.5 as soon as you can.

Ha, no I was the agent developer who put the GC instrumentation in for 1.9 :) back in 'the day'