simplify_coords function causes unexpected exit

The simplify_coords function, which uses the RDP algorithm, causes my script to abruptly (and silently) exit under both 0.3.9 and 0.4.4 (the two versions I tested).

It was passed a list of approximately 212k LineStrings (i.e. [x, y, z] elements) and exited seconds later to command prompt.

ccount = len(coordlist)
simplified = simplify_coords(coordlist, 1)
print ccount, len(simplified)

I was running my script under Python 2.7.10 on Windows 10.