I changed my template yesterday and all seemed to be well - I thought I'd plugged everything back in just fine because my blog looked pretty good. Today I checked with Pay per Post and found that my PPP tools were NOT saved. This didn't show up until today so I'm glad I checked back.
If you are a PPP blogger and you change your blog template, make sure you reinstall the tools as they will not be able to find your blog. If they can't find your blog, they can't offer you any paid posts.
Other than that little snag, I've not had any problems with the new template and am really loving the three column look rather than the two I had before.