Hi,

I'd start with that I don't have problems switching to gears - so it shouldn't be an adjustment problem.
Also down shifting (on to larger coggs) is working great and smooth.
But up shifting (on to smaller coggs) is sometimes problematic. It's shifts without problems but it seems like a a chain link is getting missed or something. It leaves a small empty gap while pedaling and my feet jump out of place on the pedals. It's doesn't happen with certain gear combinations or coggs.

I got a 9-speed cassette and a Shimano Deore RD.

I'm out of ideas.

Anybody?