Attached Link: Hi-res Square - Tripled

If you want to try it out, I've increased the resolution of the square by subdividing it, but more importantly, I've converted it entirely to 3- rather than 4-sided polys; hopefully, this will greatly reduce the occurence (it won't do so completely - there's always a possibility that the simulation will fold perpendicular to the edge of a poly) of "spikys."