Setting target links in shtml pages

I have created an html page that uses a frame. The right side of the frame needs to be changed to an shtml page in order add a server side include for the headers and the footers.

The problem is that the targets and links to those targets workedfine when the pages on the right side of the frame were html pages. When I changed the pages to shtml, the targets and links to those targets no longer worked. The links to the pages still worked, but the links to those targets did not work.

The link to the targets on the pages in the right side of frame would fail and display a “page cannot be found” message.

Why is this? Can anyone please help?