Can’t see all User Name!!!! Help!!!!!

I installed a W2K Server with W98 clients. I am trying to enable the MS Networks
File and Printer Sharing Service on all the W98 clients and use the User-Level
Access Control. So they can share their folders and files based on the user name
onthe MS network. But when I try to add user name to my shared folder, I can’t
see all the user names in the list. Then, I went to the W2K server and delete
some unused user names. After that I have see all the user name from the list. So
what Iam thinking is, there is a setting in W98 (because everything is OK for
W2K clients) to limit the number of user names show on the list.

Is there any setting like this in W98???
Otherwise, why I can’t see all the user names in the list???