This mainly applies to IIS users using php as cgi,
I had a problem I could not fix despite allowing everyone to basically anything (permissions wise

)
Anywhoo I have finally fixed the problem,
*Before doing anything check permissions on all the files*
# first off I checked my tmp dir was in the correct postition (under php.ini) it wasn't so I specified a new tmp dir and changed the dir location in php.ini.
# second I changed the timeouts in php.ini (which then caused a CGI timeout error (not the http header errors I was getting))
Now the fun part:
download Metabase Explorer:
http://support.microsoft.com/default...b;en-us;555081
then adjust this setting [W3SVC>CGI Timeout] (I changed it from 60 to 290):
Code:
Content visible to verified customers only.
and it fixed it

(some other connection timeouts can also be changed)
*Note* the CGI: HTTP header error can also be caused by permissions etc, however mine occurred on files above 2mb (timout on IIS by default is 60 seconds I belive?)
Just uploaded a 4mb file (changed some settings in php.ini as the server was resetting the connection) and it worked