non deterministic any element???

After reading the Versioning XML Languages Draft, I am a bit confused on why the any element is non-deterministic.  Below, I whipped together 3 schemas.  Say A is schema version1, B is schema version2(same namespace), and C is companyX extending version 1.  Why would the xml below the schema's be non-deterministic???  ie. if I throw doc B at a program that only knows schema A or throw doc C at a program that only knows schema B, etc.  thanks for any help in understanding here.  I am really just trying to understand section 9.1(http://www.w3.org/2001/tag/doc/versioning-20031003#d0e971)
thanks,
dean

AAAAAAAAAAAAAAAAAAAAAAAAA
<s:complexType name="CallbackType">
   <s:sequence>
      <s:element name="callbackLocation"
                 type="s:anyURI"
                 minOccurs="1" maxOccurs="1"/>
      <s:any processContents="lax"
                 namespace="##any"
                 minOccurs="0" maxOccurs="unbounded"/>
   </s:sequence>
   <s:anyAttribute/>
</s:complexType>

BBBBBBBBBBBBBBBBBBBBBBBBBBBB
<s:complexType name="CallbackType">
   <s:sequence>
      <s:element name="callbackLocation"
                 type="s:anyURI"
                 minOccurs="1" maxOccurs="1"/>
   <s:element name="NewElementInVersion2" type="s:string" minOccurs="0"/>
      <s:any processContents="lax"
                 namespace="##any"
                 minOccurs="0" maxOccurs="unbounded"/>
   </s:sequence>
   <s:anyAttribute/>
</s:complexType>

CCCCCCCCCCCCCCCCCCCCCCCCCCCC
<s:complexType name="CallbackType">
   <s:sequence>
      <s:element name="callbackLocation"
                 type="s:anyURI"
                 minOccurs="1" maxOccurs="1"/>
   <s:element name="ExtendedElement" type="s:string" minOccurs="0"/>
      <s:any processContents="lax"
                 namespace="##any"
                 minOccurs="0" maxOccurs="unbounded"/>
   </s:sequence>
   <s:anyAttribute/>
</s:complexType>

AAAAAAAAAAAAAAAAAAAAAAAAAA
<CallbackType>
    <callbackLocation/>
</CallbackType>

BBBBBBBBBBBBBBBBBBBBBBBBBBB
<CallbackType>
    <callbackLocation/>
 <NewElementInVersion2>string</NewElementInVersion2>
</CallbackType>

CCCCCCCCCCCCCCCCCCCCCCCCCCCC
<CallbackType>
    <callbackLocation/>
 <ExtendedElement>string</ExtendedElement>
</CallbackType>