Could you see if you could retrieve /var/log/installer/debug from the system, or any other logs from /var/log/installer or /var/log/syslog; they may include details on what happens during the install to explain the stalling.
Could you see if you could retrieve /var/log/ installer/ debug from the system, or any other logs from /var/log/installer or /var/log/syslog; they may include details on what happens during the install to explain the stalling.