Stackoverflow creates different accounts for one openId at google on different machines. Is there any way to use one account on all machiches?
I use the google openid, and I've never had any of these problems. Are you sure you have a registered SO account, rather than just having an unregistered account linked to your google-mail email address?
If you let me know some way of identifying your posts (any clue at all) I'd happily take a peek...
My suggestion is that you use myopenid.com (or another solid provider) instead of the Google OpenID provider.
I am sure there is a way to make the Google provider work, but there have been issues with the Google provider since the start and in my opinion it is not worth the trouble. I have used myopenid.com since I started on StackOverflow in the beta, and I have never had an issue, and I cannot remember the last time I even needed to log in. Things just work which is the only way it should be.
Once you have a solid OpenID set up, email firstname.lastname@example.org with the accounts you know of, and they can merge them.