IE7 -- Cookies must be allowed -- but they are!

[frustrated user]

I am having many difficulties with IE7 and am about ready to switch back.

Sessions are ending for no reason when switching between tabs.

Repeatedly get "Cookies must be allowed" error--when my cookies are allowed.

I have deleted all cookies, cleared cache, and temp pages and restarted.

I quickly gave up on overriding cooking handling from my normal allow 1st
party, prompt for 3rd party and always allow session cookies--to the
automatic settings.

I have changed security and privacy back to defaults.

All to no avail. Thus I can not use IE 7 any more. I am having to use
Firefox to post this message.

Is there a fix for this/these problem(s)?