I've experienced the before and the first thing you should try
is to open up 1Password and find all your Google logins.
Make sure all of them are set to the same URL/Location. If
they're all set to something like http://www.google.com it should work
If one is set to Google.com, another is set to reader.google.com
and something else is
google.com/registerationfoo/madeupurl/index.html then 1Password can
have trouble figuring out that all of these accounts belong to
Google and won't ask you which one to use.
Give that a go and if you continue to experience trouble let me
know and we'll take another look!