Articlebuilderforum? Is that the jlforum.com? I am guessing so :-)
Yep, I leave the "skip sites with PR below X" unchecked" for contextual tiers 1,2 and 3, as per Ron's advice. If you leave this unchecked then unknown PR will not be skipped.
I did first start by having the Tier 1 contextual links set at skipping PR below 3, it took a long time to get a handful of link. I then worked my way down to below PR2, then PR1, and then nothing. Nothing is a lot better!!!