I've heard that the 'sticky beads' problem is common. What we did, is I rubbed the beads back and forth, back and forth, along the wires, as much as I could stand. I'd find which individual beads were being 'sticky' and I'd spin it and rub it and press it on the wire while rubbing it...

Eventually the stickiness did wear down and it works fine now. But it was VERY annoying at first and I did have to work at it quite a lot. I'd still rather do this and have the wooden abacus than go for the plastic, but it would be even better if they were smoother.