On Thursday, 8 August 2013 07:00:43 UTC+12, Joe Marini wrote:
Extension popups are limited to 800 wide by 600 tall. If you're seeing scroll bars at around 500 there may be some padding on your body element, you can set the padding and margins to 0.
Thank you Joe. That is a very good answer. Indeed, above my 480 pixel high generated menu I have two rows of image buttons and below it a generated user prompt/status bar and so it probably does add up to 600px. With 20/20 hind sight I do wish the documentation had told me about this and also I'm still clueless how to make sure it is going to work acceptably for users with different screen resolutions.
However now that I know it's not something I was doing wrong, it's time for me to move on and do the Fire Fox version. I am glad I got my first ever extension to more or less do what I wanted and also thanks to the great community here for all the help :o)