Form Post to another URL from in HTML FRAME

I have a really odd problem.

I have an HTML page that contains two frames. One of the frames contains a
little HTML Form that I am posting to a remote server ( method = post ) when
I click the submit button.

Everything works fine in Firefox. The remote server reads the values from
the form nicely. Try the exact same pages in IE and the remote server does
not receive the form, it just sees null.

Now to make it more odd, the posting works fine if its not in a Frame. Just
simply open the HTML form in IE and everything works, and in Firefox.

So the problem only occurs when I'm posting from IE in frames.

Does anyone have any ideas what the cause mught be?