The fact that addons are compatible, by default may be nice to others, but having Add-on Compatibility Reporter addon did not matter. However, Thunderbird, which did not have the addon has been a disaster. I has told me me that the tiny (128Kb) incremental could not be applied, because another copy of TB was running. I have had the Task Manager open, and have not seen anything unusual. I tried, for the fourth time. I will have to uninstall/reinstall TB.
UserAgent: Mozilla/5.0 (Windows NT 5.1; rv:10.0.2) Gecko/20120216 Firefox/10.0.2 SeaMonkey/2.7.2