Hi Helmut,
First of all, it's good practice to ask SAP-internal questions in SAP-internal forums and not on the public forums on SCN. customers and partners do not know (or care) about our internal sandbox systems and can only be confused .
Regarding your revisions, go with 1.00.52 (latest), that one includes XS. A dev build from July 2012 can only include an outdated and incomplete XS
Cheers
--juergen