View Port Widget not working in Firefox

(I am running MODx 0.9.6.3 on a server with PHP 4 and MySQL 5)

I created a template variable with a View Port widget in order to display a non-MODx event calendar on a site page. Because the height of the calendar expands when items are added to it, I have accordingly set both the Auto Size and Auto Height properties of the View Port to ’Yes’. All of the other behavior options have been set to ’No’. (I actually had to play around with these for a good while in order to find a combination that properly responded to the calendar behavior.) Initially, it seemed as though everything was working fine, but it turns out that in Firefox 3.0.10, the View Port is only displaying a small portion of the upper section of the calendar.

Does anyone have a sense for why the View Port is not working properly in Firefox?

Thanks in advance (and always) for any suggestions.