Help needed regading Conversion from HTML to XHTML:PLZ REPLY

Hi,

I read your article on XHTML and FAQs related with it.
Coming to my point, I would like you to plz suggest me as to what is
happening wrong with my XHTML converted code.

Actually I am working on LIVESITE product by interwoven.
My page created with HTML in livesite were displaying perfectly. All the
text was left aligned.
when i converted the HTML to XHTML by parsing with XHTML converter , the
text in my pages has become center aligned. There has been no chnage in CSS.

I am unable to find out why this problem has ocurred.Is this because
conversion has not been proper or because of CSS? Plz guide me ...

Plz Reply..
Thanks in advance,
Shalini jain