That's right. Roboform is only compatible with Firefox 3.5.
This is incorrect. I have not updated my FF and I use version 3.0.13 with Roboform and have ner had any problems. Install Roboform the go to FF and install the add-on so that you can use it.
Here's the link for the Roboform add-on for FireFox...
https://addons.mozilla.org/en-US/firefox/addon/750