Hangs when updating from within page

If I update content from within the PowerCMS application it works ok.
e.g. this url
contents_update.php?ContentID=45

But when I try to update via the edit link on the website page it hangs forever when I click the update button.
e.g. This URL
cmstest.html

I've spend the entire day trying to figure out what's going on but cannot.

Can you shed some light on this please.

Both URL's are going to the same place, the only thing that I see that is different is the return page. If you remove the return page portion of the URL can you get the page to load correctly?

The return page should be set to the page that you came from when you clicked on the edit button. Where you on this html page when you clicked on the edit button? It is unusual to see a .html page as the return page.