running WSDL2Java on a wsdl that includes a simple type restriction, e.g.
<simpleType name="ID">
<restriction base="xsd:string">
<length value="18"/>
<pattern value='[a-zA-Z0-9]

'/>
</restriction>
</simpleType>

in Axis 1.1, this creates a new type called ID, with beta2, this is just mapped to string. This make existing client code (written against an Axis 1.1 generated stub) incompatible.