Thanks, Jimmy57. That is the clearest explanation of the issue I've ever seen. It sounds like I'm on the right track- the most important thing is to make sure the vvt hub is able to reach its clockwise limit with the timing belt installed, and to make sure the position of the hub relative to the cam...

If the cvvt mechanism is working properly, once you get the timing belt off you should be able to rotate the hub back and forth. Some of them are spring loaded, on my S60 it was not. This is part of the reason you need to be able to see the back end of the cam- the gear and hub mechanism can appear ...