Testnet is broken because too much power was puten there (thanks Xelister 1 and Artfortz 8 of 5970's 
It will take apparently months (with 1 5970) to reset diff to be usable by CPUs.
Is this design flaw? I think so.
Solution: lower diff also each say 72 hours passing with too few (or none!) blocks.
Also disallow overtaking network and forcing switch to own version of chain - with like totally other history for last 1 week, or 1 month, or even since the begining!
Solution: use more anchors (e.g. fixed points in chain on which everyone agrees).
Not only in source code but also distribute them. Say each 2 days?
It will take apparently months (with 1 5970) to reset diff to be usable by CPUs.
Is this design flaw? I think so.
Solution: lower diff also each say 72 hours passing with too few (or none!) blocks.
Also disallow overtaking network and forcing switch to own version of chain - with like totally other history for last 1 week, or 1 month, or even since the begining!
Solution: use more anchors (e.g. fixed points in chain on which everyone agrees).
Not only in source code but also distribute them. Say each 2 days?