License problems with informix net products on rm400 server

Hello there, i've some strange problems with client access from Windows95 to an 5.0x SE database server on a siemens rm400 system. Products on the rm400 are 4.11UC3 developement tools and the 5.08UD1 SE engine. According to the readme files which comes with the two tapes, i installed first tools message files and then server messages files. Now i installed the developement tools, then the SE and at last the net component. Finally, i had to install a siemens license disk (32 user license). All steps are done with pkgadd. The clients are using the ESQL/C runtime 7.x. Also i've installed the dbaccess tool. I did the necessary settings in the windows services and hosts file and also the setting in informix\\etc\\sqlhosts. On the server machine, i wrote a startup files for the sqlexecd which makes the appropiate setting for SQLEXEC and starts sqlexecd. I'm using port 1540 for the connection. What happens when a client tries to access the database server is the following. On the client side, i always get error -928 (database server not licensed for remote data distribution). The sqlexecd on the server side shows me an entry like "sqlexecd pc72 kgs -p" but nothing about any missing license. I really have no idea if i'm missing some very important part during the installation or if this dammed key system has some serious bugs. Greetings, Joerg