No access to PCI Board Register

I use some industrial PCs (Tetra 2 from Logic Instrument) on Windows NT
4.0 with a PCI Board /driver developped on DDK.

On some PC, I can read the PCI config Space and after the
HallAssignSlotRessource, HalTranslateBusAddress and MmMapIoSpace functions
calls : No access to any registers is provided : The registers seem to be
well readed but no writing is possible ! I try to write a value in one of
the register and I always read 0xFFFFFFFF.

  • What is strange is that the base address 0 is 0xD3000000 and after the
    HaltranslateBusAddress() call : the virtual adress is the same and it is
    the same for BAR 2. (the board is plugged on Bus number 2)
  • All functions calls are correct and report any error !
  • Nothing appears on the PCI Bus during access to register (spied with Bus
    analyser )
  • No ressources conflict could be noticed ! (the board is the only PCI
    board connected on)
  • On some other PC, all is correct (All access are provided) The board and
    the driver have been fully tested.

Could you help me please, I don’t understand anything
I suppose that it is a problem of Bios version …
Is it a problem of driver ?

Many thinks for your help,