Just something to think about. Entourage keeps all of its mail, calendar, etc in one giant file. If you get file corruption there, it will redefine sucking for you.

I used to use Entourage but switched to Mail. I have two keychains and never had the problem you are describing. Mail and Entourage handle the keychain differently though. Entourage will keep accessing the keychain each time it needs a password. This can keep the keychain active if you have them getting locked after a certain amount of time, but you need to check your mail more frequently than the Keychain locking itself. Mail, gets the passwords once and then the Keychain can lock itself and mail won't care.

Well i had a similar problem but i kept the second keychain
What i did is open keychain access then click on the new keychain. in the edit menu go to "name of your keychain" Settings and change the settings to not check after time inactivity and not to lock when sleeping. then it will ask you on once or never depending on the keychain rights.