Help Latitude D830 stripping bytes

I am seeing a stange issue with the Dell Latitude D830.  And of course these laptops seem to be the laptop of choice for most of our distributor  sale force.

So I work for a company that makes programmable motion controllers and  I'm trying to set it up with the D830.  But for some reason the data transfers are not happening as expected.  So I put a network analyzer, using Network Spy and Wireshark, on the D830.  And I see the packets are missing bytes.  I then put a hub between and another computer also running a network analyzer.  The second computer, a desktop with a Netgear FA311A NIC, sees the entire package on the line.

On the D830, I've disabled Windows firewall, the anti-virus, and I believe I've opened it.

Our application is a winsock app that open the port and then writes packets and looks for responses.

The application works on every desktop, including Dell's although we do not have any newer Dell that are within a year old,  IBM Thinkpads, like the T41's, T42, T60's.  It even works on a MacBook Pro running bootcamp and WinXP.  They work on HP laptops and Toshibas.  I only seems to have a problem with these newer Dells.

I also have a sales person who re-insatlled a fresh copy of WinXP, normal version, not from the Dell Recovery disks and his works fine.  So I think it is something with the extra Dell software.

I have also used a third party usb-to-ethernet adapter and it has the same problem.

Here is a sample of the kind of think I am seeing on the network analyzers
D830 sends 4 bytes
    00 1b 00 ff
D830 expects to recieve 36 bytes
(usually comes in 2 packets a packet of 20 then a packet of 16)
    00 1b 00 ff 00 00 00 00     
    00 00 00 00 00 00 00 00 
    00 00 00 00
    9f 9f 13 00 00 00 00 00
    00 00 00 00 00 00 00 00
   
D830 only gets 28 bytes
(came in a packet of 20 then a packet of 8)
    00 1b 00 ff 00 00 00 00     
    00 00 00 00 00 00 00 00 
    00 00 00 00
    9f 9f 13 00 00 00 00 00
   
Any help is greatly appreciated.
William