That happened to me once too, but I don't have a proxy (unless my ISP has one for some reason).

Brion Vibber <brion@pobox.com> wrote:

On Tue, 2003-05-13 at 01:50, Ray Saintonge wrote:
> 1. In editing the [[republic]] article I chose to split out a small note
> about Republic Aviation Company to its own stub. When I put the
> material I put the name of the company in bold. When I saved I received
> the message about there being no text on that page. In edit mode the
> text popped bnck up. I added the word "The" at the beginning of the
> article, and it saved just find.

I've been hearing a number of complaints recently about similar behavior
(not properly reloading after saves, in particular). This sounds related
to client-side caching; in particular those using proxy caches or whose
internet providers force proxy caches upon them seem affected. There may
be a difference in how the cache control headers are sent due to a
recent PHP upgrade, but I haven't had a chance to check for sure yet.