oh and... we started putting the site on the server at the mid of the month... around the 15th, 16 or even 18th
I just checked the webalizer stats for that month again:
user agent #1 with 48%:
Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)
user agent #2 with 22%:
Mozilla/5.0 (compatible; Yahoo! Slurp;
http://help.yahoo.com/
;)