checker) when the number of nodes is greater then 100. There appears to
be a pathological problem in Jacks that causes it to consume 100% of
your CPU for 5 minutes or so before finishing. The was making it
impossible for David to do his 200+ node tests.

Addendum: while testing this just now, I noticed that the problem is
related to the cross product of nodes and links. 100 nodes and no links
is actually not that bad, but add a lan and watch out!