Changing file extensions and duplicate content

[alphacooler]

I recently changed my site over from static html pages to dynamic php pages. I am curious as to whether or not this sort of thing could trigger duplicate content filters. Anyone have any experience with this?

[Mike12345]

Have you deleted the files with the old extensions? If not then you have two different files with the same content, therefore the possibility of a duplicate filter being triggered is raised.

Also, something to bear in mind is that you may see a drop in rankings because the files with the new extensions will be treated as new, and all your links etc will have been pointing to the old files.