There as some changes in the way "This Month, This Year, Monthly Records and All Time Records" are dispalyed which is due to the new .NET formatting of dates and times.
I updated the wt_data_inc, wt_data_intl, wt_month_inc and wt_month_intl files on the Weather By You site ( see http://weatherbyyou.com/forum/index.php?topic=1255.msg4302#msg4302
. Have also attached them to this post if anybody wants them.
If you follow the link above it will explain differences and has links to 2 sites which demonstrate the differences.