Pete,
 OK, so it sounds like it used to work but no longer does.  Most likely this is a function a change in your internet explorer or netscape settings, as BeerSmith uses these functions to display print preview.
 We did have one instance of this with a user  who had recently changed his netscape settings.  When he set his browser settings back to the default settings it cleared the problem up.
 Also - are you running Windows 98-Me or Windows 2000-XP?  If you are running Windows 98 you need to make sure you have all of the second edition updates and the latest version of Internet Explorer.
 By the way - you can always work around this by going to the "My Recipes" view and selecting the recipe you want to view and then setting up the preview pane to display the brewsheet.  You can also print the brewsheet from this view.
 Hopefully one of the above will help - but let me know if you are still in limbo!
Cheers!
Brad