Ok I did some debugging with php streams to figure out what the server was returning when sending the above junk (note that it DOES work when only sending about 10 lines ok) here is what your webserver is returning when sending the above junk:
Code:
HTTP/1.1 302 Found Date: Fri, 29 Aug 2008 13:10:47 GMT Server: Microsoft-IIS/6.0 Location: http://localhost/removecookies Connection: close Transfer-Encoding: chunked Content-Type: text/html; charset=iso-8859-1 11b
Found
The document has moved here.
--------------------------------------------------------------------------------
http://localhost/removecookies?
Apparently the server is automatcially trying to redirect me when sending a lot of data (this was never a problem until about 2 days ago - my code has never changed in years)
Doing a google search on this message reveals that it's the webserver settings protecting itself - so you obviously have changed a setting somewhere that does not like a certain amount of post data going through..
PS I've tested this on my other content site and that has the same problem (hosted on the same server) with the HTTP:302 redir on posting above x amount of bytes in a form!