Software Deployment

I have been distributing flash player 9.0.124 in a company environment successfully on about 1800 machines, the only ones posing a problem are virtual pcs that have been staged with vmware.

here is part of my cmd file:

Xecho "If old versions are installed, remove them "
if exist %systemroot%\system32\macromed\flash\*.ocx source\uninstall_flash_player.exe /silent
xpstat -wait uninstall_flash_player.exe -t 120
Reg Query "HKLM\Software\_company_\Installed" /s | find /i "Flash Player 8.0.24.0 (Macromedia)" && packmancmd /U 20070102173258 && Xecho "Cleanup of old version for Packman "
Xecho "Launching Latest Flash ActiveX Plugin "
copy /y "Source\install flash player 9 ax.exe" "%temp%" > NUL
"%temp%\install flash player 9 ax.exe" /s
xpstat -wait "install flash player 9 ax.exe" -t 300
del /q "%temp%\install flash player 9 ax.exe"
REM Xecho -l "%$pkg_logpath_network%\%$PKG_Foldername%\%computername%.txt" Installation %$PKG_Foldername% ended ...

according to the log file everything has been uninstalled/installed fine, but on the vpcs I get consequently two application errors logged, the first one:
-Faulting application uninstall_flash_player.exe, version 4.0.0.8, faulting module nsisarray.dll, version 0.0.0.0, fault address 0x00003a6b.
second one:
-(drwatson)The application, Z:\Flash Player 9.0 (Macromedia)\source\uninstall_flash_player.exe, generated an application error
The error occurred on 07/07/2008 @ 18:16:25.171
The exception generated was c0000005 at address 00993A6B (NSISArray)

untill now found nothing that references to the nsisarray.dll which is used during the installation.

why does this occur only on virtual machines, driving me mad !
(all machines, virtual and non virtual run the same OS: XP sp2)