SAP Business Objects Win AD Authentication Error: User Not able to log in

Hello together,

two users cant login into bi launchpad (SAP BO 4.0 SP2) but all other users can.

Error Message:

Account Information Not Recognized: Active Directory Authentication failed to

log you on. Please contact your system administrator to make sure you are a

member of a valid mapped group and try again. If you are not a member of the

default domain, enter your user name as UserName@DNS_DomainName, and then try

again. (FWM 00006)

Any ideas what the problem is?