I'm using FastCGI via IIS7 to host a PHP application. For whatever reason downloads that are streamed via PHP (i.e. a script that outputs a file/bytes as a response) download perfectly fine on high-speed connections but on anything slower (even on DSL) quits at EXACTLY 4128760 bytes (~3.9MB) - which makes me think it's a configuration issue... We only started having this problem when we switched from Apache to IIS - this also points to a configuration problem, I think.

But if it's a configuration issue, why would it only affect slower connections? Does anyone know where (or how) I could possibly change a setting like this? I've tried changing the idleTimeout, executionTimeout, and activityTimeout values in my web.config but this hasn't helped at all. Any help or direction would be greatly appreciated. Thanks in advance.