I had reason to pull up my MacBook's activity monitor while running Chrome (6.0.408.1 dev) in OS X, and I noticed that there are multiple entries for a process called '1Password for Chrome (Chrome Plug-In Host)', the older ones consuming 3.4MB of memory, and the newest a full 12.5MB. Closing 1Password and Chrome do not remove these processes, so I think something is going wrong on cleanup. It's version 0.7.2 of the 1Password extension.
Please have a look!
Thanks. And thanks for the constant improvements to the plug-in. I'm looking forward to the day when it's as polished as those for other browsers on the Mac.