What we have determined is that the 3594 drivers will load properly on a clean install and should be the first device installed, if possible. The procedure is as follows:
1) Boot machine. 
2) When Windows finds the PCI Communications Device, let it search for the driver. 
3) A dialogue box will appear asking for the location. Go to Browse, then to "A", then to 3594W9x.
4) Click "Next", then when prompted, Finish 
5) It will then look for the Wave Device for Voice Modem, follow steps 1 - 4. 
I have enquired of Robert Chechi at 3Com about this issue, to try to make the modem easier to deal with and as soon as they have updated drivers I'll forward them to you. In the meantime, use the following files for Windows 95, 98 and Windows 2000.