Get archives theme code

Hi,

I have been having problems with the wp_get_archives code and I found this on the forum that seemed to help https://www.ads-software.com/support/topic/displaying-archives-by-month-excluding-a-category?replies=5 however, now when i use this code (see below) I get a list of archives by month in my navigation but for some reason posts that have been published in January 2011 are being listed as january 2010. Following posts are listed with the correct year, it is just january that has the previous year attached, does anyone know why this might be?

[Code moderated as per the Forum Rules. Please use the pastebin]