I honestly don't know why it does that.
I know however, that you can change the format file and set the column as SQLCHAR (leaving your table intact) and let it do an implicit conversion. That should give you the correct results.
Luis C.
General Disclaimer:
Are you seriously taking the advice and code from someone from the internet without testing it? Do you at least understand it? Or can it easily kill your server?
How to post data/code on a forum to get the best help: Option 1 / Option 2