tedster - 9:37 pm on Jan 9, 2012 (gmt 0)
It can take some time to recover rankings after changing URLs and instituting 301 redirects. The more technically precise those redirects, the shorter the recovery time, in general. Backing out of that kind of change can often make the recovery take even longer, because you've now built a more complicated history for the site.
Redirects and refreshes are a long-time spammer's playground and Google needs to verify all such changes for trust - that's what takes time, in my understanding.