Which version of Reader you are using?
It Is Adobe Reader 9.2
There was a browser bug with IE in the past that seemed to span several browser versions. It had to do with the interaction of the browser and the webserver. The short version is that I had to toggle the caching option on the folder.
Here's what I ended up doing for my client:
- Move their PDF documents into a subfolder called forms and all Flash animations into a subfolder called flash
- Marked all folders in the site to "Expire Immediately" (IIS -> highlight root folder -> Properties)
- Individually marked the "/forms" and "/flash" folders to toggle this caching option
In this way, it allowed dynamic pages to deliver non-cached content (from the server's perspective) and it allowed binary downloads like Flash animations and PDF files to work as expected without errors. The bug has to do with the cache-negotiation handshaking that goes on between the browser and server.
This may not be what you're seeing but it's good to remember because I've seen it often: the settings that you'd use to optimize a web applications don't seem to work for binary downloads like a PDF document.
you could also try:
a. installing updates until you get to v9.4.4 or
b. install Adobe Reader X, then update it too.
c. open control panel add/remove programs, select Reader, then click change, then click repair.