IE Cookies issue - really need some help

[eluser]new_igniter[/eluser]
I am using the default CI cookies and am having this issue where after a while, people login, but it just takes them right back to the login. It doesnt go through validation. There is no message returned. This continues until the cookies are deleted from the browser.

Can anyone offer any advice? Its a growing issue and I am new to this.

UPDATE - so this seems to be an IE, CI_sessions issue, where my users cannot create a session. Does anyone know a way - outside of using a different authentication system, to solve this issue?

[eluser]tomodian[/eluser]
Are you developing in local environment?

If your local domain contains '_' underscore, IE cookies & session don't go well.

For example, both 'localhost_dev' and 'localhost_test' doesn't work. If so, change them to 'localhost-dev' or 'localhost-test'.