Return of bad symptom

[1993CivicVX]

Some of you may remember last year after I bought my VX I had a lingering idle problem. The symptom was that right after I'd shift the idle would go up slightly--hang out--and then slowly drop down again instead of dropping immediately. Well, recently I had the alternator replaced, the water pump replaced and the valve cover gasket replaced by a new mechanic and the idle problem came back!!

Now this doesn't make sense to me.

The way the idle problem was fixed the first time was by cleaning out the throttle body. Is it possible my mechanic somehow fouled up the throttle body while doing the above described repairs? Any ideas? I am going to speak to him today. The symptoms were immediately evident as I drove out of the mechanic's garage.
Thanks,
Jason

P.S.
I forgot one other thing. The alternator belt was also replaced and now makes an ever so faint squealing noise after I start the car up. My car has never made a squeaky or squeal noise from a belt. Not sure if this could have any bearing on the issue.