[wp-hackers] Error in 2.5

[Mário Gamito]

Hi,

I've upgraded from 2.3.3 to 2.5 and well went well and is fine, except 
in one point:

After I publish an article, if I later go back, change it and click 
"Save", I get this blank error page with the text:

"Not Acceptable
An appropriate representation of the requested resource 
/wp-admin/page.php could not be found on this server."

Nevertheless, the changes I make, do appear in the blog.

Is this happening to anyone else around here ?

Warm Regards,
Mário Gamito