My RD is skipping and I'm unable to find the sweet spot on the barrel adjuster that will stop it. I took the bike to the LBS last week and they did their best, but it still skips. I fiddled with it this week and all it did was get worse so I've taken the bike back to the LBS. What do you suggest?

It is a shame to use up my free tune-ups when this is the only problem on the bike.

The bike came with a 105 10 speed chain, a 105 FD, Ultegra STI shifters, IRD cassette and a long cage Ultegra RD. My chain broke in August and I fixed it. There was no problem skipping before the break or after the break. Then last week I replaced the chain with an Ultegra directional 10 speed chain. I've had the skipping problem ever since. I didn't keep the old chain so I can't swap it back onto the bike to see if that fixes it. The LBS says the new chain is compatible with the other parts.

I'll pick up the bike on Tuesday and hope it is fixed. Otherwise, what do you suggest?