User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:188.8.131.52) Gecko/20100722 Firefox/3.6.8 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:184.108.40.206) Gecko/20100722 Firefox/3.6.8 Some compatible extensions get magically "not compatible" from time to time. When this happens, it's enough to click the "Find updates" button in the Add-ons dialog, and they magically (again) start working. Later on, they get not compatible again. This happens when restarting Firefox or the OS, but now always. It doesn't depend on updates to Firefox nor to any other extension. This has been a long time issue for me, specially with the Brazilian Portuguese dictionary. It happens now with another extension (URL Alias), so I've understood it's an overall Firefox issue. I'll attach some screenshots of the issue. It always happens with both extensions at the same time; never for one of them only. Reproducible: Sometimes
I'd bet is report is invalid, and the compatible version range of your addon is at fault. Did you check the addon's version range?
I have lived with this issue, constantly, with Firefox 3.6. It seems stable now with FF4.
Thanks FredCK. We use WORKSFORME when we don't have a patch or don't know what resolved the issue