I have 1Password 5.3 (Mac App Store) installed in OS X 10.10.3 and 1Password 188.8.131.520 installed in the Windows 7 Boot Camp partition of the same Mac.
I sync my vault via Dropbox, and it's syncing properly between the two OSes.
Anyway, I noticed something weird: in the Mac app, Watchtower shows no vulnerable logins. In the Windows app, however, it shows 6 Watchtower vulnerabilities and 2 Heartbleed vulnerabilities.
That seems pretty weird. Why do the two apps have different criteria and/or databases that report different things on the same vault?