The Big Question.

Why MS Using Such kind of Board when they know this problem will occur..

High density
The BGA is a solution to the problem of producing a miniature package for an integrated circuit with many hundreds of pins. Pin grid arrays and dual-in-line surface mount (SOIC) packages were being produced with more and more pins, and with decreasing spacing between the pins, but this was causing difficulties for the soldering process. As package pins got closer together, the danger of accidentally bridging adjacent pins with solder grew. BGAs do not have this problem, because the solder is factory-applied to the package in exactly the right amount.

Heat Conduction
A further advantage of BGA packages over packages with discrete leads (i.e. packages with legs) is the lower thermal resistance between the package and the PCB. This allows heat generated by the integrated circuit inside the package to flow more easily to the PCB, preventing the chip from overheating.

Low Inductance leads
The shorter an electrical conductor, the lower its inductance, a property which causes unwanted distortion of signals in high-speed electronic circuits. BGAs, with their very short distance between the package and the PCB, have low inductances and therefore have far superior electrical performance to leaded devices.

BGAs find some use in security-sensitive applications, especially where it is impossible to prevent physical access to the chip. For instance, a ROM chip with a BGA configuration is considerably more difficult to access than one in a DIP or TSOP layout. Tracing circuit paths to the BGA chip is limited by the contact points being obscured by the chip itself.

Foxconn are the Major of all motherboards man~.

but what makes me intrested that MS actually "don't know" these problem?

Such a Big Company (actually there are the Biggest in the world liaw) but don't know this problem ?

They didn't test their beta unit or whatever long enough I guess?
I mean it takes quite a while for the xclamp to give in..

I think most probably is due to the pressure. Just tune it back to the "right" pressure and it will be fine... for some time Still, there is going to be immense stress on the chips if you keep doing it that way, and since the console acts up after hours of gaming proves that the chips are starting to get sensitive.

Just a mindless theory of mine though...