Web-to-Lead from Sharepoint

We use MS Sharepoint as our company Intranet, and are attempting to set up a web-to-lead form to allow employees to submit leads. The form works fine from a regular HTML page, but does not work when we make it part of a Sharepoint page.

Does anyone else have success with a web-to-lead form from Sharepoint? Any insight you can share?

Thanks so much.