I have an application that I wrote that allows users to upload files (pictures or PDFs). I am using IIS 6 and php 5.4. The problem I am having is that it seems like file uploads are getting cached somehow. For example, if I upload the same file over and over it works just fine, but as soon as I upload a different file, that particular file and anyone after it is corrupt when trying to view it after it is uploaded. Once I do a hard refresh (Ctrl+F5) in the browswer, the first file works fine again when uploading, but as soon as I upload a different file it becomes corrupt. I am using Google Chrome and IE9.
session_start(); at the beginning of page doing the uploading.
tacked on a timestamp to the end of the url doing the uploading.
Checked to php max_upload size (which is fine).
Immediately expire content headers in IIS.
It almost seems like an IIS problem, but I could be wrong. I hope I posted this in the right place, and any help is appreciated.