As I've written in my post above it does not crash immediately, at least it did not in my case. Over a couple of years every now and then I tried a different puzzle solving algorithm (for the puzzle "Eternity II"), for instance one that would trace the board in a spiral:



The recursive structure of my first algorithm used a function as follows:

void solve_step(...)
{
var tile_array[1024];
var used[256];
...
}

It seemed to worked flawlessly until a good number of pieces had been placed but then it would just go into a wrong direction for a couple of pieces (for no apparent reason) before crashing.