thank you craig.
we now have a workaround from IBM:
ln -s libclntsh.so libclntsh.so.9.0 in ORACLE_HOME/lib.
So the oraoci9 stage thinks it works with oracle 9 client, but does work with oracle client 10.
I am not so really amused about it, but at the moment it seems to work. Does anybody think that telling the oci9 stage it dieals with oralce 9, but it is oracle 10 client, could cause errors?
In 7.5.2 we had not this link and oci9 stage worked fine with ora 10 client.
I asked IBM, but got no answer to that yet. Maybe I have to ask them twice.
Transformer: C Stage PlugIn function "Put" require
Moderators: chulett, rschirm, roy
From a pure Oracle standpoint, there is no backwards compatibility. You should always use the "least common denominator" approach: of all of the Server versions you need to connect to, use the client from the lowest version. I've never had an issue over the years with that approach but the opposite was not the case - you are asking for trouble using a higher versioned client to connect to a lower versioned server... it may seem like it works but will eventually turn on you and bite you right on the... nether region. 
-craig
"You can never have too many knives" -- Logan Nine Fingers
"You can never have too many knives" -- Logan Nine Fingers