So Frank has I said on my response this was a BUG.

>Response from MS.
>
>
>I tested with your XML file. I get a C0000005 error under the released
>version of VFP7 with the following command:
>
>?XMLTOCURSOR('P000001522.xml','ctest',512)
>
>This is due to a bug with XMLToCursor() and XML containing a high number
>of fields. It is a function of the total length of the fieldnames.
>Depending on the number of fields and the lengths of the field names, it
>can occur with 100 to 170 fields. Your example has 162 fields. Also
>depending on the exact XML, you may see an error or a fatal exception.
>
>We are aware of this one already, look for it to be addressed in the
>upcoming SP1 release. I suspected this was the case, but I wanted to
>verify you had not found something new.