The dialogue box is a by product of the headers, they’re still there, open LiveHTTPHeaders in the sidebar of FireFox and you’ll see 'em. 
Okay thanks, here are the results:
Admin:
HTTP/1.1 200 OK
Date: Mon, 06 Dec 2010 11:48:07 GMT
Server: Apache
X-Powered-By: PHP/5.2.14
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Content-Disposition: attachment; filename="Hello.pdf"
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 3488
Keep-Alive: timeout=10, max=30
Connection: Keep-Alive
Content-Type: application/pdf
Client:
HTTP/1.1 200 OK
Date: Mon, 06 Dec 2010 11:46:51 GMT
Server: Apache
X-Powered-By: PHP/5.2.14
X-Pingback: http://www.davisinv.com/xmlrpc.php
Content-Disposition: attachment; filename="Hello.pdf"
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 392
Keep-Alive: timeout=10, max=30
Connection: Keep-Alive
Content-Type: application/pdf
Even when I remove the Content-Length header from my code, it still appears as “Content-Length: 392” on the response header (client side)…
Any idea guys? Thanks…
I’m all out.
The headers are identical, barring the content-length, so it’s definitely down to the retrieval of the PDF content I’d say.
Are you using a different method of obtaining the source data? What about output buffering, could this be in play?
I am using the exact same function to get the source data as I am from admin…that’s what makes it so strange!! Not sure about output buffering…how can I test that?