I have a page class with several HTMLText fields, one of which didn't end with "Content". This worked fine on my local WAMP server, but when i uploaded it to the production server, I got a 404 error when saving that page (just like like what this thread describes, even though the situation is different). I got the 404 error only when I tried to write more than one paragraph to the field in question. Long story short, when I renamed the field to end in "Content", the problem disappeared.
This begs the question, why? Is there something special about fields ending in "Content"? And why would my WAMP server be immune while the production server returns a 404 error? What's triggering the 404 error (which is clearly misleading, as the error isn't caused by a missing page, or bad URL)?