site.monthlist bug?

The site.monthlist macro is not working correctly anymore at my site The "August 2002" link starts at my first entry in September 2002 and the "July 2002" link starts at my first entry in August 2002. You can see yourself. I used the macro as specified in the macros section. It did work properly until today. I have made a lot of changes today, but I suspect it may have something to do with me changing my timezone to be Australia - I am only guessing though.