Not sure whose responsibility this bit of code is, but Sun's C compiler reports a divide by zero here: cc -DNDEBUG -O -c /home/skip/src/scipy/special/cephes/kolmogorov.c -o build/temp.solaris-2.8-sun4u-2.2/kolmogorov.o "/home/skip/src/scipy/special/cephes/kolmogorov.c", line 47: warning: division by 0 FYI. -- Skip Montanaro skip at pobox.com