Ok, I've recently converted one of my sites to php. The pages did have just an html extension. The PR seems to have disappeared completely overnight.

Will Google spider this and consider it duplicate content and penalize the site? If so, will it be spidered again when the cache is gone, and how long do you think it will take for that to happen?

Really, I mean I've worked my tail off to get the PR I had and literally overnight...poof!

Use a good .htaccess redirect method to redirect your old html urls to new php urls.

PR for php pages will be worked out by google only after a few weeks, after when your site is indexed by google ( with new pages).

It won't be considered duplicate content if the PHP pages replace the HTML pages (since there will be no point in time where both copies exist at once).

Hmm, both pages do show up when the entrie url is typed in. Would that be the cache of the old pages?

The html pages were deleted from the server so the php pages could replace them. How would G drop the PR and not index at the same time?

I don't think Google penalized you. (at least not for creating a php version of your site) If you are sure your site is removed from the server you may be seeing it from your browser cache or perhaps your ISP has cached it. You may have your browser settings set to only check for new pages after a certain amount of time.

Most likely your PR will come back within a few more days. (or a few months if they actually did penalize you)

-Ginty