In a dev environment, there are debug builds and there are retail builds. And there are debug builds that get mistaken for retail builds...
Here's a quick way to see if the binary in question is a debug build or not:
PSH> (Get-Command kernel32.dll).FileVersionInfo.IsDebugFalse
Good. I'm not running a debug version of Windows. Thought not.
Now, if only someone could explain why in PSH2 they decided to duplicate this functionality in Get-Item, but expose the property as VersionInfo, I'd love to know.