Did you make sure the keg just isn't hidden behind miscellaneous loot, or something?
Kordoba's suggestion was the lost item procedure, I just elaborated on it a bit and added the necessary inventory files in case people didn't have a previous save to go back to. If you read through the procedure a couple time, it may not be nearly as scary (as long as you are at least familiar with Windows Explorer and moving files around).
Thanks for mentioning the broken link; I fixed it.
Check your messages (click 'My Stuff' in the top menu bar, then 'Messages').
