I am running in to an issue with generating apex code using a WSDL. The generated apex code does not seem to recognize the <xsd:extension> tage. Is this a known issue? 

Here is the WSDL snippet:

<xs:complexType name="Account">
<xs:complexContent>
<xs:extension base="snet:BaseObject">
<xs:sequence>
          <xs:element minOccurs="0" name="Reference" type="snet:AccountReference"/>
          <xs:element minOccurs="0" name="AccountName" nillable="true" type="xs:string"/>
           <xs:element minOccurs="0" name="AccountNote" nillable="true" type="xs:string"/>
           <xs:element minOccurs="0" name="Status" nillable="true" type="xs:string"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>

However, the generated Apex code, does not seem to extend the BaseObject.

 public class Account {
        public uriSubscribenetIntrawareCom.AccountReference Reference;
        public String AccountName;
        public String AccountNote;
        public String Status;
        public Boolean AccountNoteToNull;
        private String[] Reference_type_info = new String[]{'Reference','uri:subscribenet.intraware.com','AccountReference','0','1','false'};
        private String[] AccountName_type_info = new String[]{'AccountName','http://www.w3.org/2001/XMLSchema','string','0','1','true'};
        private String[] AccountNote_type_info = new String[]{'AccountNote','http://www.w3.org/2001/XMLSchema','string','0','1','true'};
        private String[] Status_type_info = new String[]{'Status','http://www.w3.org/2001/XMLSchema','string','0','1','true'};
        private String[] apex_schema_type_info = new String[]{'uri:subscribenet.intraware.com','true','false'};
        private String[] field_order_type_info = new String[]{'Reference','AccountName','AccountNote','Status'};
    }

Any ideas on how to get around this issue?