I downloaded this firefox sample extension from mozilla.org, I modified the file install.rdf and changed maxVersion value to 3.6.10 (also tried 3.6.*, 100 and *) and I added a new sting with name "hello world" and the value is the path where the folder of the sample extension is to HKCU (also tryed HKLM)/Software/Mozilla/Firefox/Extensions/ into the registry.
I start firefox, go to Tools > Addons, and it says it needs to restart, I restart and go there again and the plugin appears but says "Not compatible with Firefox 3.6.10", and every button appears disabled. Also removing the registry key and folder doens't uninstall it.
Is there something else I have to change to use the hello world sample in Firefox 3.6.10?