I am running a Drupal 7 site and am noticing a problem on IE9, when the browser window is closed the user is logged out. We have "remember me" module enabled and the cookie is set to not expire. There is no issue on Chrome or any other browser, you can close browser and when you open it the user is still logged in. I do not not see this problem on any other D7 website I run using this same browser and computer. The host is Blackmesh.
settings.php has $cookie_domain = '.mydomain.com';
I am thinking of changing this to $cookie_domain = 'www.mydomain.com';
as the site always redirects to www this makes sense to me and is what me and my sys admin friend agree on.
One potential solution I am thinking about is setting cookie domain in settings.php $cookie_domain = 'www.mydomain.com';
I am noticing there are some cookies on the site being served from www.my domain and some from .mydomain
I found some threads that seem to have vaguely similar problems.
http://forums.modx.com/thread/76947/ie-login-issue-with-www-vs-non-www-address