Google Adword Antics

What’s with Google suddenly de-activating words that were just running in another campaign for 5 cents per click and saying I need to raise my bid to $1 to activate them in a second campaign that has an entirely different landing URL?

I used Ad Words Analyzer, a great little tool, to refine the words for the second campaign, thinking I had done a much better job with this campaign, and that the clicks were about to begin to whirr in, but when I got to the point of estimating traffic in the Adwords tool, I noticed my prize word was marked inactive and that to activate it, I needed to raise my bid to $1. I checked the old campaign and it was still active at a nickel. Goo figure.