I have an 800363 that I am mounting on my project rifle as soon as the stock gets back. I haven't used it yet but the scope appears to be stout and very clear. I own a few of their 800325 Grand Slams with the EBX and they have been awesome for hunting purposes, never an issue.
I imagine they'll send you a new scope for the trouble. Chances are something went bad or was bad from the factory on an erector or internal. This is the first time I have heard of a issue like that with one of the higher end Weavers. Like SSA said, mine is stamped Made In Japan.