Sync problem between a QTEK 9100 & Windows vista

Hi,

can anyone help me solve following problem. I have a QTEK PDA / Phone i
connect via USB cable to a laptop.
The laptop, a fujitsu-siemens runs Vista Home Premium.
The QTEK runs Windows v5.0

The firewall used is the one Gdata internet security suite.

I disabled the suite completely and installed the WMDC 6.1.
Upon connection Vista does start install the drivers for the PDA but it
stays disconnect after all is done successfully according to vista.
I looked further and discovered some kind of network connection is created
to the PDA but it shows 'limited connection'. I suspect that is the source of
the problem of absence of detection of the PDA. Even with all firewall
activity suspended, and everything else i tried, (repaire connection,
déactiviation/ activition) no action i took solved this problem.

I really would appreciate to be help on this.
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Kind Regards,
Henri