mysql,asp vbscript

i have a content entry pages... that i used standarad charset and everything
worked fine.
now, i am requested to change the charset in these pasges to utf-8
all is well... i store the content nicely... but one problem occured
i have a date field in mysq
in the content entry pages, i let the user choose the time to make the
content live by using 3 drop down menus
one for year,one for month, and one for day...
when the user submits the data... he goes to a preview page.. where he
submits the record to the database, or goes back t edit it
on this page, i put the values of the drop down menus in one hidden field
and i insert them to the db..
but when i view the the record in the database... its not storing the the
date he entered.... it stores the default value which is 0000-00-00 00:00:00
anybody got a clue? the only thing that changed in these pages is the meta
tag only