MSD Mechanical Advance not returning to stop postion-anybody else have this problem?

[RestoCreations]

My MSD 8594 Distributor has an interested issue with the mechanical advance.

I could not figure out why the car was having such a difficult time starting and would kick back. Well, yesterday i took the distributor cap off and went over the weight system. It turns out that the mechanical advance is not returning to the stop position about 90 percent of the time, which leads to the ignition being in almost full advance at start up.
So, i took the distributor out and cleaned off the corrosion that had already built up on the shaft directly underneath of the sleeve that has the prongs/arms on it that the mangentic pickup assembly reads its signal from. I put a small amount of lithium grease under the sleeve and did my best to work it up and under the assembly. HOwever, i did not want to leave too much lubrication on the shaft, as i figured it would just sling off and cause the magnetic pickup to fail. I have tried using every combination of spring to see what would help return the advance mechanism back to its stop point, but no combination solves the problem. If i turn the assembly by hand when installed, it will return, but once the car is run, it jambs up.
I called MSD and they want me to return the distributor, but I know they are going to say that it was my fault because I had the iron gear replaced with a steel one.

Anyway, anybody else had this problem?