Client in win98 cannot register callback if both side auth level is CONNECT.

Hi ,
I have a DCOM program, Client side is running on
win98,server side is on
WinNT 4.0. There is a callback in the program, when I run
the program
running to DispEventAdvise, try to build the connection
point, a error message pop up, authenticaion service is
unknown. I check my
configuration on both side, if I set both side
authentication level is none,
there are no such problem. But if any side of them has
authentication
connect level or above, the error will pop up again.

So is it the only choice to set both side authentication
none. or what
should be configured to use higher authentication level.

Any help appreciated!

Jason