opera v7.54 for linux is only partially working at best.
The HTMLarea defaults to plain text, many visual glitches, etc. Not sure I'd put it on the "works with" list for G-O.
From my Damn Small Linux install, I also know that Firefox 0.8 worked with everything except the HTMLarea...it didn't even give me a "plaintext" option the way opera did.
Just for fun, I loaded up Knoppix 3.6 and a spare system and had a look at my G-O installation with Konqueror. Everything seemed to work, but overall it seemed a little glitchy visually (table alignments and borders, etc). I had to fiddle with my browser identification string to get the HTMLarea editor to turn up, and as far as I could see it was only coming up as the plaintext form window.
It'd be nice if we could get G-O working on at least one of the older/lightweight browsers (links -g, dillo, older firefox, opera) for making older machines into functional office-drones.