We had one site where google set silly min bids on our most effective keywords. When I say most effective, I mean keywords that result in user sign-up, disproving google's theory of lack of relevance
Anyway....
We changed nothing and just left them de-activated and played some more with MS Adcentre.
After a couple of months, went back to adwords only to find that Google had come to it's senses and allowed us to re-activate at the original price.
Perhaps The big G was trying it on, but cos we were stubborn and big G was a little strapped for cash, they had a change of heart.
Must admit, in limited experience, when google isn't going bid crazy, Adcentre performed better for us than Adcentre, but that's another issue.