Some people are unable to provide comments with their own identities using their Google accounts, because blogger always mistakenly tags them with someone else. Clearing cookies and cache for the browser won't make a difference. I am one of them. Thus, I won't comment friends' blogs with my Google Account identity because it will never be me. Luckily most of them allow visitors to sign with Name/URL.
I just did a little bit experience using a public computer where I have never been before by posting a comment back to my own blog. When I posted a comment, I logged in with my Google account, hoping my name will show up correctly. No, never! Instead, I became someone else. The worst is that I don't even know who that person is. Obviously, it is not the issue of you possessing many Google accounts as blogger claims. Unfortunately, blogger has never admitted the fault and has no plan to fix it. In looking back the complaints posted to the blogger user communities/forums, this problem has existed for a few years already. To be safe, if you have already experienced this problem, it would better not use Google account when you post a comment to blogger, use OpenID if you have another identity with some other sites, or use Name/URL if the blog allows anonymous posting.
Blogger cannot correctly handle their own Google account for comment posting. Why not put Google account under OpenID category and handle it the same way as other OpenIDs? This problem discourages people using (or signing up) Google accounts and also degrades user experience.