You're lucky. The maddening thing is that you can SEE it switch to the proper altitudes, but it doesn't "catch," so it "snaps  back" to a plan without a TD. So clearly it "knows" what it is supposed to do, but for some reason it can't bring itself to do it. I confess I finally gave up on the 767 over this issue. It is character flaw in me that I find it difficult to shrug off things like this. An FMC that can't reliably do the bare minimum of handling a route with basic VNAV just isn't going to work for me.

Don't get me wrong, I like Captain Sim and have most of their products. But a TD bug that was driving me nuts nearly three years ago should really be fixed.

Where do you get your routes? Is it possible you are doing something different than other people are doings? If you fly much at all in the Captain Sim 757 / 767 then odds are you should have run into it, but you haven't. What's the difference?