Indenting in HTML mode

[Tyler]

Hi,

I'm trying to edit an HTML file, and I am unable to indent lines with 
the tab key. The only thing that I've managed to make work is to mark a 
region, then C-x tab to indent that region by 1 space. Also, on text I 
have yanked into the file from the clipboard I can tab as expected. 
However, all the text I entered directly into Emacs is 'protected' from 
tabbing. What am I doing wrong?

Thanks,

Tyler