Update:

I finally got some wrench and riding time on my Semi Pro. I changed out the chain, the rear derailleur cable, and replaced the RD OEM housing with Shimano SIS housing. I then went out and did some hill riding and experienced no ghost shifting. In fact, up and down, it shifted great. Better than ever.

It sure is nice to climb some hills and have both hands on the bars.

Thanks for the help!