First link in Page content changes to download link

I am building a site using several plugins including Protected Content and MarketPress.

Recently the first link on several pages is being transformed from the url we gave it to a download link.

In WordPress Page the link is set to:

But when you view it on the site it transforms to:

This has happened on 2 other pages so we just removed the links for now. But I caught this one this morning and thought I'd see if anyone has any idea what might be going on.

We have tried to change how the link is created WP 'Link' by selecting a WP Page and hand typing in the href via Text by an Admin or Author account.

Any help would be appreciated.