Hi,
I think the error is in choosing the incoming datatype (I know for sure this is the reason you get the error). The input parameter is now a blob reference, but I think you want it as a char (probably 128, because this is the maximum table name length).
Now when you execute the function you give a string (char) as parameter, but the function is created with a blob as parameter. So this can't be the functionm you requested (IDS thinks). This behaviour is called polymorphism and is used across several object-ralational engines.
Drop your function and recreate it with:
CREATE FUNCTION desc (mytable char(128)) RETURNING int,varchar(50),int,varchar(50),int,varchar(40),va rchar(25);
etc...
This should work,
Rob Prop