Ever since Apple started provided iTunes version 4.7 for Windows, we've had
considerable trouble getting the Music Store working through BorderManager.
Version 4.6 for Windows works, and I believe v.4.7 for MacOS X works
properly. I've attempted to contact Apple, but so far the only response
I've received about it is that the 4.7 adds the "Proxy-Connection:
Keep-Alive" header to HTTP requests.

We're using the latest PROXY.CFG from
http://nscsysop.hypermart.net/proxycfg.html and we have
"RestartTimeoutAfterEverySend=1" as recommended by TID10059667.

Does anyone have any suggestions on getting iTunes to work through a
Bordermanager proxy?