Hi,
I faced the same issue on Lion OS. I am not able to download apps from App Store even on Snow Leopard.
This is the console log generated on Lion OS:
9/19/11 2:51:48.946 PM App Store: FRPurchaseManager: Preflight operation for 448457090 failed with error: Error Domain=com.apple.appstore Code=0 "The product distribution file could not be verified. It may be damaged or was not signed." UserInfo=0x7ff0744910f0 {NSLocalizedFailureReason=Cannot create PKProduct from "file://localhost/var/folders/jn/kzl_8zs11s9390s93k3rh__00000gp/C/com.apple.app store/448457090/preflight.pfpkg" Error Domain=NSURLErrorDomain Code=-1100 "The requested URL was not found on this server." UserInfo=0x7ff07448bf80 {NSUnderlyingError=0x7ff07422cef0 "The requested URL was not found on this server.", NSErrorFailingURLStringKey=file:///var/folders/jn/kzl_8zs11s9390s93k3rh__00000g p/C/com.apple.appstore/448457090/preflight.pfpkg/index.sproduct, NSErrorFailingURLKey=file:///var/folders/jn/kzl_8zs11s9390s93k3rh__00000gp/C/co m.apple.appstore/448457090/preflight.pfpkg/index.sproduct, NSLocalizedDescription=The requested URL was not found on this server.}, NSLocalizedDescription=The product distribution file could not be verified. It may be damaged or was not signed., NSUnderlyingError=0x7ff0742bc700 "The requested URL was not found on this server."}
I tried to delete the file preflight.pfpkg in the same path. Launched App store but no luck, the same error is thrown again and again. Even I logged-out and relogged-in but still the same error.
There is same error on SnowLeopard. If I use reliance netconnect, I am able to download other apps except xcode 4.1, as it requires Lion OS as the current OS before downloading xcode 4.1. (Xcode 4 can only be downloaded on LION OS)
Problem is I can download apps from App store of Snow Leopard using reliance netconnect but not xcode 4.1.
And I tried to download xcode 4.1 from App store of Lion using reliance netconnect, but reliance netconnect usb modem is not getting detected on Lion OS.
Can someone help me on solving this issue? And I wanted to know whether this problem is related to App Store or Network?