Problems establishing JCO connection

I keep receiving the following error message when testing my JCO Connection in Web Dynpro Content Administrator:

Connect to message server host failed Connect_PM  TYPE=B MSHOST=evivax 
GROUP=Entwicklung R3NAME=EVX MSSERV=sapmsEVX PCS=1 LOCATION    
CPIC (TCP/IP) on local host with Unicode ERROR       service 'sapmsEVX' unknown TIME        
Thu Jun 19 13:23:07 2008 RELEASE     710 COMPONENT   NI (network interface) 
VERSION     39 RC          -3 MODULE      nixxhsl.cpp LINE        643 DETAIL      
NiHsLGetServNo: service name cached as unknown COUNTER     38

Does anybody have a clue whats going on? Is my SLD entry for the target systems message server wrong or what not?

Thanks, JJJ