Thanks, Michael. And sorry about the repeated question. As a newcomer, I wasn't quite sure how this works. If you notice, I originally posted my situation at the end of the original (4/09) thread, but then I realized how old that thread was, and I was afraid that my comment wouldn't even be noticed by anyone, so I repeated it as a new question, just to make sure someone might see it.
Anyway, thanks for the suggestion. I did do everything on the Microsoft support site (Mr. Fixit, upper/lower registers, etc.), and none of that was successful. My ribbon cable is shared with my hard drive, so I cannot place the jumper on the DVD/RW in the "Master" position. Also, I doubt it is a bad cable, as the same problem is ocurring with two different PCs.
I'm planning on sending these drives back to HP, and will try my luck at Comp USA or some local retailer. So for anyone that now searches this Users Group with a problem concerning the HP dvd1140i DVD/RW, my advice is, "buyer beware."