I currently have Firefox version 3.6.10 and 1Password for Mac version 3.4.3 BETA-3 (Build 30763).
I have noticed on the past several updates to 1Password that several of my Firefox plug-ins get disabled by performing the 1Password update. After I perform such an update and I then open the Tools/Add-ons dialog box in Firefox I see several plug-ins grayed out and with red exclamation points next to the add-ons icon. (Please see attachment) If I click the "Find Updates" button in the Add-ons window, and then restart Firefox, all of the add-ons start working again. It sure would be nice if the 1Password update did not do this!