Over the weekend I was riding bike I haven't ridden in about a month. The last time I rode it, it shifted perfectly. This is Campy Record 8 speed. Right from the start of my ride, on the small ring in the middle gears, it is now shifting properly down into the cog path and then immediately moving a little further and up and seemingly riding in between the two gears while the crank just spins freely. This is also happening while in a stand with no load on the bike. This is happening on two or three gears. What could be causing this and what do I need to looking for? Thanks!

Is it possible that the derailleur hanger is bent?
Have you checked the chain for stretch?
Have you tried adjusting the shift cable at the barrel adjuster?

Al

sounds like simple adjusting or damage. try doing an adjust, if that gets you no where have the lbs check it out for damage.

Well, the bike's been parked since the last time I rode it, so I am sure it must be an adjustment. Thanks for the responses and I will report back when I identify the problem.