I'm starting off with a very simple modification to default, but I'm already getting myself into trouble. All I did was make my own logo.gif, and replace the one the default theme came with. And of course, it was warped by the height and width attributes that were set for the XOOPS logo, rather than mine. So I dropped the attributes from theme.html and uploaded ... but it's still warped. The theme.html file has no height and width attributes, but they're set in the HTML being produced by xoops. Where is it resetting those attributes?

Goto admin, system, site preferences, general settings, and set "Update module template .html files from themes/your theme/templates directory?" to yes. Once your site has gone live and attracts a lot of visitors, you should turn this option to no. Enabling this option decreases xoops' speed.

good luck!

Worked perfectly, thanks!