Certain HDRI files produce noisy output in current svn compared with the 0.1.1 official release, please see attached images.  I tested with some popular HDRIs from the Debevec website, namely the St. Peters and Galileo probes.

This may be a recurrence of an old bug that was fixed prior to the 0.1.1 release, information on this is found in the following forum thread:

http://www.yafaray.org/community/forum/viewtopic.php?f=13&t=2061

I am also attaching the blend file I used to test with, but I didn't pack the HDRIs.  Please go to Debevec's website for the image files if you don't already have them:

http://www.debevec.org/probes/

I used the angular map versions of these HDRI probes.