Hi Hal,
If it works and is only giving a "Slot not specified" message, then all may be well. As noted in the NIF file, the Intel Gigabit drivers (from at least v3.6x upwards) are not supposed to have a slot ID configured for single card use.
When no slot is specified, the driver should report that it was not specified and that the driver will be "using card in slot ID ____"
If it is doing that, successfully loading the driver, and successfully working; then the message is simply informational and can be ignored. If it is failing along the way or requiring you to hit a key to continue, then you have a problem.
On another note about these chipsets:
There are other performance related parameters that go with this card as well, but I would try them at your own risk (they control memory buffer use, etc) - as using too high a value will cause your machine to trap (regardless of which driver you use). The defaults seem to work adequately enough.
Robert