Firefox sending two get request for a website

Question

Clicking a link results in two calls for the page to the server. I install livehttp and inspected the header but can't figure out why it's sending the second request.

http://example.com/schedule?delete=290376

GET /schedule?delete=290376 HTTP/1.1
Host: example.com
User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20110207 Firefox/3.6.13
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive
Referer: http://example.com/schedule
Cookie: Code=XXX; CodeHash=XXXXX

HTTP/1.1 200 OK
Date: Tue, 01 Mar 2011 22:09:51 GMT
Server: Apache
X-Powered-By: PHP/5.2.17
Set-Cookie: Code=XXXX; expires=Wed, 02-Mar-2011 00:09:52 GMT; path=/
Set-Cookie: CodeHash=XXXX; expires=Wed, 02-Mar-2011 00:09:52 GMT; path=/
Keep-Alive: timeout=2, max=200
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: text/html
----------------------------------------------------------
http://example.com/schedule?delete=290376

GET /schedule?delete=290376 HTTP/1.1
Host: example.com
User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20110207 Firefox/3.6.13
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive
Referer: http://example.com/schedule
Cookie: Code=XXXX; CodeHash=XXXXX

HTTP/1.1 302 Moved Temporarily
Date: Tue, 01 Mar 2011 22:09:55 GMT
Server: Apache
X-Powered-By: PHP/5.2.17
Set-Cookie: Code=XXX; expires=Wed, 02-Mar-2011 00:09:55 GMT; path=/
Set-Cookie: CodeHash=XXX; expires=Wed, 02-Mar-2011 00:09:55 GMT; path=/
Location: http://example.org/schedule?errors=5
Keep-Alive: timeout=2, max=200
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: text/html
----------------------------------------------------------

Answer 1

In case you didn't find your solution:

I have stumbled on that same issue, and it seems to be related to the page encoding. If FireFox downloads a page containing invalid characters (for example, utf-8 chars inside a page for which the Content-type header is something else), then it will download the page a second time and parse it in the encoding it has tried to guess from the invalid chars it detected in the first page.

So make sure your page either returns the correct Content-type header, or contains a meta http-equiv header with the correct encoding.

Answer 2

You don't happen to be using firefox, have the web developer toolbar and also have the display page validation on do you?

I am guessing in the dark here as to your enviro but my team and I have been able to demonstrate that having that tool bar installed in firefox and having page validation set to display actually duplicates the POSTs and GETs as it sends that same page data to the validation service.