pd devel_0_39 did also set the DAZ/FTZ flags, which affect the denormal handling on the sse unit, but that was never merged into vanilla pd
I see there's a new pd_devel branch. I should check it out.
i doubt, that the new pd_devel branch shares anything with the old pd_devel except for the name ... also, please note that daz/ftz only deal with the behavior of the sse unit ... if your external is compiled to use the fpu, you will still see performance issues, when denormal numbers occur
best, tim