Caching and Product AutoUpdaters.

I noticed today that Adobe Acrobat 9 Professional wasn’t able to download updates when “Help .> Check for Updates” is selected from within the product. Using Wireshark, I obtained the URLs used to request updates from Adobe. Comparing the results inside my network to those outside of the network, I determined that the BlueCoat proxy on our network had older page cached.
The cached statistics for that page claimed that it had verified with the server that it had a current copy of the file. I blew away the cached content and set to ‘no cache’. The Adobe Acrobat client was then able to see that updates were necessary.
The Adobe server used eTag. That should have prevented this problem.
Caching can cause issues. When it causes issues with autoupdate mechanisms, would you even notice.