I'm getting these white boxes after the preloader image with a single hemisphere.

also there is no loading bar.

Has anyone else had this problem?

thanks

That's the back (empty) half of your single-shot image.  The viewer image is still a complete 360 degree sphere but your scene is only using half of the sphere.  Pan the image and you'll quickly understand.  By editing the pan, tilt, and fov values (3 each, in the panorama script) you can precisely control how much of the sphere your audience can view.

Is it all done by trial and error or is there an easier way to do this?

Is there a common setting?  Any help is greatly appreciated!

I also have PTViewer Scripter 1.3 if that helps.

A splash image might cover up the white box grid.Y  ou might be able to use <param for a  'Wait' or splash image to be displayed while the image is downloading.  

Just a thought

Dave