Hi,
In my case, PO version is 7.31 SP09
for SAP Enhancement Package 1 for SAP NetWeaver Developer Studio 7.3 SP09 PAT0002 --> TPZ export worked
for SAP Enhancement Package 1 for SAP NetWeaver Developer Studio 7.3 SP04 PAT0004 --> TPZ export failed
May be you can try with latest NWDS version for your PO7.4 SP05 version
Regards,
Praveen Gujjeti