Hi Jaxz,It is workable, I've done. If memory serves me correctly you do need to use DOC TYPE on each page. For example:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
Since Activ uses IE for rendering the pages the quirks in IE still apply. Frankly, I don't recall having to use any hacks to make the drop down menus happen. Javascript was used to make the navigation panel remain in a static screen position, which means you don't need to be concerned about "position: fixed" property in CSS/IE.
When working with CSS normally the best practice is to design against FireFox, then after everything is working the design is adjusted to work in IE. Of course when designing ebooks you only need to design against IE. I mention this only because it is a deadly trap to design for IE first if you also design web pages.
