How to access addressbooks through Login not MultiLogin

Hi，

Could anyone tell me how to access the address book through GWAccount generated by "Login()" method (can not use "MultiLogin()")? when I did this in C#, I always got the error "The 'MAPI Session Handle' of the Novell GroupWise 'Object Request Broker' could not be accessed. The address book cannot run(error status: 0x80004005).".

Thanks!