Ok, so let me just get this staight. You have been successful in setting the bead, but it holds for 48 hours or less? Now I have stans'ed Conti's before, granted, they weren't supersonic tires, but didn't have too many troubles. I know with Kendas, half the battle is sealling up all the tiny little pinholes in the casing due to such a lightweight design. Maybe you have a similar problem. In that case, you gotta keep working the stans in at a higher pressure. As you get to the higher pressure, you will probably start to here a bit of hissing as little holes open up. Be careful because I believe there is a pressure limit on the rim itself, so don't exceed that. Also, it's been more than once that a customer brought in a brand new set of stans wheels that were "pretaped" and we had to retape them to work. In most cases, a faulty rimstrip is visible and sometimes when installing the tire, the tape can catch on the tire and lift up on you. And just make sure you have the right valve stem in there. Stan makes an olympic valve that is only for the olympic rim with the yellow tape and he makes one for everything else. If you have an olympic rim, the rubber head of the stem is much smaller and is just a little bigger than the valve hole. The standard valve is much larger and won't sit correctly in the "valley" of the rim
You chose the lighter setup, but not exactly the most durable reliable setup. As for Stan, he has some great products, but he would make a great used car salesman, if you know what I mean. It's okay to admit that a product has some shortcomings once in a while.