I seem to have an odd problem

i use Class aaa // common class
{String a=null;
String b=null;
String c=null;
}
class bbbb extends aaa
{String d=null;
String e=null;
String f=null;
}

Call Bean ( (aaa) bbb) gives Class cast error
when passed to the BEAN ???? !!!!!!



can anyone explain ???
can anyone suggest solution ????


thanks