If the letters within a Hype text box are overlapping / having negative kerning or whatever, this is odd. Check the HTML for the box and see if there is anything strange there. If that doesn't provide a solution, post your Hype document on the forum and perhaps Daniel or someone could take a look at it.
Also, do you have the text box set to ignore browser settings? ( Inspector > Document tab > Advanced > "Protect from external styles" )