Mark -- I concur. When I first started wearing zero drop shoes, I experienced quite a bit of calf pain high in the calf, where the tops of my calves attached to the back of the knee. But the pain radiated into the knee joints (both legs, but more so on my left, which is the foot that pronates more).
It never went away until a summer where I spent the entire summer in zero drop shoes (even for casual use), and regularly hiked in them 5-10 miles a day 3 or so times a week, with lots of multi-day backpacking trips thrown in.
Now, I don't have that pain anymore, and wear zero drop shoes almost continuously.
Unfortunately, now it's winter, and I'm back in my Inov-8 288's, which are a far cry from zero drop, and I have some plantar and metatarsal pain from re-adapting to them. I might have to do some heal shaving on them.
Also: it's worth noting that if you have something that works, then it's going to be hard to argue for change. One "theory" upon which this whole minimalist shoe thing hinges, of course, is the longer term (over the course of many years) benefits to the joint system resulting from wearing this type of footwear, which is supposedly less taxing on the joints (due to the increase in total muscle fiber contributing to propulsion -> better stress distribution). I suppose biomechanically, there should be some merit to it but we just don't have long term data for us weekenders, and whether or not we'll see those benefits.
Finally, the Trailroc would certainly be an improvement. I just wanted to stick with shoes that I had first hand experience with, and I haven't tried the Trailrocs yet.