I struggled with a similar fuzzy text problem with Premier Pro 1.5 and I found this to be the only solution:

select the footage on the track below your text and add an effect to it - any effect will do. Now adjust the setting of the effect so it does not actually effect the footage (for example turn it down to 0). This seems to sharpen the text on the track above. Don't know why, but it does.

Hope this helps

robin