Firefox login/cookie problems

I’m having problems involving possibly cookies & login. Often, but not always, when I open a new Firefox browser session (I’m using Session Mgr. so I’m essentially reopening tabs fr. the previous session), instead of opening the page from my blog the tab takes me to a login pg.

When I go into the Firefox cookie cache I see the following cookies:

ww.wp.xz.cn utmc
wordpress. org utmz
ww.wp.xz.cn utma

But when I go to the WordPress.com cache I see a cookie called WordPress Logged In. Shouldn’t I see a cookie like that in WP.org as well? I also notice that after logging in I still see the same 3 cookies listed above.

I don’t know whether the problem here is Firefox not generating the proper cookie or whether there’s a conflict generated by WP. If anyone has any ideas or has seen similar behavior pls. let me know.