Hello Bodis,
If you're using v1.0 of CX-Server OPC, then yes, you probably will have some problems. (Isn't this the case with any software marked version 1.0 ???).
I can categorically state that v1.21 is completely OPC compliant (to standard D.A. ver 2).
I suggest you contact your local rep for an upgrade - this should help with any problems you may be having.