I ran across a Web page describing a Russian film tank once. (Unfortunately I don't have a bookmark.) If Crio's tank is like the one I read about, it can't be inverted; agitation is done solely by twirling a knob, IIRC.

Perhaps adding a bit more solution to the tank (if that's possible) would help matters. Since you say your first home-developed roll was OK, try thinking back to how you agitated and otherwise processed that roll. Did you do anything differently from the way you did the subsequent rolls?

As a last resort, if you can buy something via eBay or an online merchant, you could buy a new (or used) non-Russian tank. If that's not possible and you want another tank, perhaps you could arrange a trade. (I might even be willing to buy a used tank off eBay to trade you, just for the novelty of having an old Russian tank. )