spinbuttons
When we were working on the last version of Forecastfox, we tried to use spinbuttons in the options dialog to limit some input. Spinbuttons however are broken badly right now in Mozilla so we had to drop them. For us the main problems were that there was no native styling and no images in the default theme. There are some other issues with spinbuttons as well, but they really didn’t effect us. I even requested blocking status for Firefox 1.1 in the hopes that this would be corrected, but Asa Dotzler denied my blocking request.
It looks like Daniel Glazman is now doing some work on spinbuttons for NVU. Hopefully these changes will make it back into the Mozilla source, and someone will get the native styling working.