I'm running: Windows 7 Service Pack 1 64 bit, 1Password extension 3.9.19, Firefox 23.
Since the upgrade to Firefox was applied, my 1Password extension is behaving strangely. It opens ok, and lists my logins,
When I click the > to access settings such as the "submit" drop-down, the 1Password window goes blank. The options for the dropdown control actually appear in the lower left hand side of my browser window (opposite corner from where the 1Password window is), and even when selected the window remains blank. The only way I can see information in the 1Password window again is to close Firefox and reopen it.