I'm not sure this solves your problem, but here goes anyway:
The TVLink is needed to change channels at the TV2 site; nothing to do with MCE.
At the MCE site (TV1), MCE automatically selects which channel (TV1 or TV2) you will watch. For example, if you are recording something using TV1 and you wish to watch something else, MCE will automatically switch to watch on TV2 whilst still recording on TV1. There is no built in way of swapping your watching between TV1 and TV2 on the MCE side. You can of course fool the system into swapping between TV1 and TV2 by starting to record on the channel you are watching and then change DSTV channels.
You can set up your watching and recording priorities using a program called MCETweak (if I remember correctly), but the fact that you cannot 'hotswap' between TV1 and TV2 using your MCE remote is frustrating.
Good Luck - Mully