You need an 80 pin cable to use the ATA-100 interface. It has individual ground lines with each signal line to allow the interface to run faster without signal degradation. If you don't such a cable, it'll run at a slower rate (-66 max I think). Note that, IIRC, if you've got a slower IDE device on the same channel as an ATA-100 device, the interface will run at the slower interface speed. So if you want to get the maximum benefit of an ATA-100 channel, use only fast devices on it (i.e. don't put a CD-ROM with your HD).

I take it as an information message if the system boots and runs fine. If it doesn't run, then I guess you need to buy/install the proper 80 pin Ultra ATA-100 cable.

HTH.

Cheers,
Scott.