no IMAP connection on outlook 2000

Hi to all,

This is my first post to the new BBS. Thanx to my friend Arie.
My question is this: I recently started using outlook 2000 instead of outlook express 6 on win98 se. My account was an IMAP instead of pop3. This is because I have a modem connection and the IMAP gives me chance to delete messages without downloading them. After I installed Outlook I imported everything including my rules. The first time I used outlook everything worked fine.
When I used it for the second time a small window keep cropping up asking me to enter my user name and password. This I find weird as both are already written. I press ok but after a while the same window appears. I created a pop3 account and everything worked fine then (i.e. I could download all my emails straight to inbox). My good friend Arie told me that it is a common problem with win98 and office 2000. What is the problem and is there any thing that I could do to rectify it. I really need to use IMAP as sometimes I receive large mails from friends and would like to leave them on the server to view them from work because there we have a 1 megabit adsl connection.

Thanks for all your help beforehand