IDES ECC6 EHP6 SAPinst error 'SAPSSEXC_12' ABAP import is interrupted

Dear SAP Gurus,

We are trying for some time now to setup an IDES ECC6 EHP6 demo system in order to evaluate EHP6 benefits for our business requirements which willhelp us to decide if it worth going for an EHP6 migration on our ECC6 productive system.
So far we haven't been able to achieve this installation because of a systematic error code 103 on ABAP import step.
This is always the same error apparently related to EUDB table & file SAPSSEXC_12.001 (find below short extracts of corresponding logs). We've searched for solutions on SDN & more widely on the web and every similar issue seems to come from a corrupted media file problem. But we downloaded the IDES EHP6 export files more than 5 or 6 times and we even purchased the DVD/BLURAY export from SAP and restarted all over again using the freshly obtained medias but we keep having the same error again and again...
Our sandbox is a little Virtualbox i7 16GB RAM SATA hardrives.
We are running Windows 2003 server 64 with last SP & upgrades and Oracle11.2.0.3 which is correctly up & running.
All checks regards TNSlistener, services,network, hosts, general variables, SID, PATH, ORACLE_HOME, JAVA etc... have been set, tuned & checked.
So everything seems fine on the OS & DB side as we were able to setup & run successfully an IDES ECC6 EHP4 system and a CRM 7 IDES on
the same landscape without any problem.

Could you please help us to understand & solve this blocking error?

Thanks in advance

Ismael

Extract from
import_monitor.log :
TRACE: 2013-04-13 21:39:33 com.sap.inst.migmon.LoadTask
run
Loading of 'SAPSSEXC_12' import package is started.

TRACE:
2013-04-13 21:39:33 com.sap.inst.migmon.LoadTask processPackage
Task file
generation for 'SAPSSEXC_12' import
package:
E:\usr\sap\ECC\SYS\exe\uc\NTAMD64\R3load.exe -ctf
I
\\vboxsrv\SAP\51044815_1\DATA_UNITS\EXPORT_1\DATA\SAPSSEXC_12.STR
"C:\Program
Files\sapinst_instdir\ERPEhP6\AS-ABAP\ORA\CENTRAL\DDLORA.TPL"
SAPSSEXC_12.TSK
ORA -l SAPSSEXC_12.log

TRACE: 2013-04-13 21:39:34
com.sap.inst.migmon.LoadTask processPackage
Loading of 'SAPSSEXC_12' import
package into database:
E:\usr\sap\ECC\SYS\exe\uc\NTAMD64\R3load.exe -i
SAPSSEXC_12.cmd
-dbcodepage 4103 -l SAPSSEXC_12.log
-stop_on_error

ERROR: 2013-04-13 21:40:17 com.sap.inst.migmon.LoadTask
run
.
Process 'E:\usr\sap\ECC\SYS\exe\uc\NTAMD64\R3load.exe -i SAPSSEXC_12.cmd-dbcodepage 4103 -l SAPSSEXC_12.log -stop_on_error' exited with return
code 2.
For mode details see 'SAPSSEXC_12.log' file.
Standard
error output:
sapparam: sapargv(argc, argv) has not been
called!
sapparam(1c): No Profile used.
sapparam: SAPSYSTEMNAME neither in
Profile nor in Commandline

Extract from SAPSSEXC_12.log :
(DB) INFO:
EUDB created #20130413214017

(RFF) ERROR: read from data
file
"\\vboxsrv\SAP\51044815_1\DATA_UNITS\EXPORT_1\DATA\SAPSSEXC_12.001"
failed
current
table was "EUDB"
(RFF) ERROR: OS error message: Invalid argument
(DB)
INFO: disconnected from DB

E:\usr\sap\ECC\SYS\exe\uc\NTAMD64\R3load.exe:
job finished with 1
error(s)
E:\usr\sap\ECC\SYS\exe\uc\NTAMD64\R3load.exe:
END OF LOG: 20130413214017