IIS download problem

[defuseme2k]

I have a problem with our Antivirus solution here where I work. I'm completely baffled, so hopefully someone here can help. The definitions are downloaded via http, via an IIS website hosting the files. One of these files is key to the whole thing. The MIME type for this file is set to octet-stream. Just after the definitions are updated, I can do a file compare (fc /b file1 file2) between a unc path to the file, and a copy of it downloaded via http. This comparison will spit out a lot of differences. If I do an iisreset on the webserver, and redownload the file via http and compare that to a unc path to the same file a second time, there are no differences.

Everytime my antivirus updates, I'm having to run iisreset, otherwise the hashes don't match and the clients fail to update. Any ideas? I'm at a loss, and so is the support for this software. It appears to be a problem with IIS, but I haven't gone so far as reinstalling... yet.

 

[defuseme2k]

A quick update here, that I can produce the same result of an iisreset by simply recycling the application pool this particular part of the app is using. Now I'm unsure if it is their code or what.