I have tried to add this address to my address book. Normally, one clicks on the icon and a pop-up appears to modify information and confirm entry into address book. This address always shows up as "not in book," clicking has no apparent effect, until one checks the address book and now duplicates exist. First image you can see that Freeman is in the address book Second image you can see that Tbird thinks the address is not in the book Third image after I've clicked and no apparent action is taken, a duplicate appears. When this bug first appeared I had clicked on the icon multiple times, and multiple entries appeared in address book. I deleted them all, tried again, bug still happens. 139.0.2