Phil Evans spotted a problem in the new release when using an annulus region type. The region filtering is performed correctly however the WMAP created is too small in the case when the WMAP and image coordinates are the same. This is actually an error I introduced in the cfitsio code (which is however not used internally in cfitsio so doesn't change its standard use). A work-around is to use the elliptannulus region type instead of annulus. I also have a fix within the extractor code to get around this.
This bug is important for Swift analysis.