I've noticed this interesting behavior for about a week now. I know that it's cookie related, but clearing cookies/cache and all user data hasn't resolved the issue.

In all of my other browsers, logging into Google Voice (GV) while already signed into my primary Gmail account correctly opens up my primary GV account.

Currently, surfing to google.com/voice shows the log in page (while I'm already logged into Gmail in the same browser). Subsequently, logging into GV then logs me out of Gmail. I can't have Gmail or GV, or any other Google Application open in the same browser. In fact, I can't even view a google.code project page. I have to open all of these sites in an Incognito browser instance. This is completely unacceptable.

Has any of you encountered this issue? I would really appreciate some input here.