Obviously I wasn´t the only one...

having problems boiling my pasta - I found this article from 1991 just the other day... Q & A: Chicago Tribune  (it´s about boiling pasta, and it also explains the physics behind overboiling).

Laws of nature

The starch in pasta reacts similar to the fat in milk when boiling, it makes a thin layer at the top of the fluid... That layer acts like a lid, and when the fluid starts to boil it pushes that layer in the only possible direction - upwards.

Fluids has a lot of characteristics, except being wet - one of them is to find the easiest way forward. Or out, when boiled in a pan. In a regular pan the easiest way out is up, or vertically, which sometimes results in overboiling.

The easiest way out in a geyser pan is to the side, or horizontally. This results in a small temperature decrease which stops the boiling process and calms the surface down a bit - no overboiling. Simple as that.