Outlook 2007 keeps prompting for password

One of the user is facing this issue in my company. No other user is facing this issue. When ever he start out look 2007 one dialoag box is coming for authentication. After giving username and password ( remember password check box selected) also it is again asking same window after some time. So it is annoying user and me to !
user was upgraded outlook 2003 to 2007. No other changes he done. After some investigation i have found solution. He is using Windows XP OS and Exchange 2007 we are using.

Resolution
Close outlook
Control pannel –>User accounts –> Advanced Tab–>manage password–>Add Exchange server name, Username.
Removed outlook anywhere option from outlook.
Open outlook–> It will again ask for password. Give it and select remember password check box.
It worked for me like a charm. I have seen in news groups with same issue and other resolution. Any how it resolved my issues . So i thought to share my experiance, may be it will help some one.