Dumb HTML question.

<span title="Foo.">Text.</span>
creates
Text.

Mouse over 'Text' to see.  In Firefox, I can type for rrroughly 80 characters before it trails off into an ellipsis.  In IE6 and IE7, though, the text wraps.

Why is this?

How can I get around it*?

* Let's assume that I, being smart, already know the "Make it less than 80 characters" answer.