Need confirmation on 'two marble for one' geo skill causing no marble being found.

On the science thread, I've seen two people post that the 'two marble for one' skill for your geologist can also make it so there's a chance you don't find any. That doesn't make sense at all, and I'd think that maybe they were just full of marble, but then more than one says it happens and fairly often and I don't put anything past BB anymore.

Can anyone confirm it happens, if it's a bug or if it's designed that way? Or maybe if you have one open marble spot left to find, the system gives you the 'you can't find anymore as you're full' message because you found two instead of one and doesn't give you just the one instead??
Thanks

I've gotten that message before and I think that the next time I logged in the new mine was where I expected it to be. The next time it happens I'll try refreshing to confirm.

yes, it happen to me sometimes..