Use "PD_BIGORSMALL" instead (I thought PD_BADFLOAT wouldn't be the right name for a thing that was getting close to denormal. The new PD_BIGORSMALL zeros anything whose exponent falls out of the range (-64,64) -- assuming I've coded it right. This fixes underflow problems with delay loops, for instance, and also protects agains unstable loops overflowing.
oops ... sorry, i read -1e19 instead of 1e-19 ....
cheers ... tim