Thats a Micosoft IE thing. Firefox, Safari, and Netscape all use it now.
You have to enter SHIFT ENTER for a carriage return.
This interface is a javascript call that causes a text box to handle as if it were like a word document.
I stole the code.
There's a lot of odd things about it too.
Sometimes, if the focus gets confused, entering a space in the text box causes it to toggle from text to display mode.
Oddly enough, MySpace and some other sites use the exact same code.
I think its annoying to have to enter SHIFT ENTER for a carraige return!
I have to do that in some Word documents too. hmmm.
Its kind of like having to enter ALT ENTER in an Excel's spreadsheet text box to get your heading in to be two lines.
And it seems like, at work, if I enter SHIFT ENTER in outlook, it will just send my email before I'm done..youch.