I recently discovered a post and page title conflict with Twenty Twelve theme. My blog's title "Around Android" was being displayed like this:
A PostAround Android | Around Android
While it was supposed to be like this:
A Post | Around Android
I've spent hours looking for the issue. And then suddenly I discovered the issue is happening to Twenty Twelve theme only. I rolled back to Twenty Ten or Twenty Eleven and the problem disappeared. Then I reactivated Twenty Twelve and deactivated All in one SEO pack plugin only to see that the problem was gone!
That made me believe the plugin has some sort of conflict with Twenty Twelve theme. I've tried everything possible and the result was always same.
Twenty Twelve + All in one SEO Pack = Duplicate Title
Any other theme + All in one SEO Pack = OK
Twenty Twelve + Deactivated All in one SEO Pack = OK
Requesting plugin author's attention.