Forums not accepting cookies

I have two sites I recently transferred over from another host, however, neither site will allow you to login. The one site, once you login, it just keeps re-loading the login page, the other (message boards) tells you that you have logged in successfully, however, when you click to return to the main page, it still shows you as logged out. The code is the same as the previous host, nothing has been changed, so it all should work, but I’m not really sure what else to try.

During transfer, has the domain stayed exactly the same?

Could you try clearing your cookies and logging in again?

If not, paste (from your phpBB configuration):
Cookie Name
Cookie Domain
Cookie Value
Cookie Secure
and Cookie Length