Adding a Search Plugin for Firefox Via Extension is done using bundles, putting your .xml OpeSearch in /searchplugins/ directory and Firefox will automatically add them when the Extension is installed.
See https://developer.mozilla.org/en/Bundles and also my own question Including a Search Plugin in my Firefox Extension
Well, it worked fine, until i started using Firefox 6. It seems that Firefox 6 does not read the /searchplugins/ directory anymore and does not add the Search Plugin. It might be also Firefox 4 and 5, i jumped from 3.6 to 6 directly.
Any idea if this is a bug in Firefox 6? Any idea how to by pass it and install the SearchPlugin Anyway?