Wow-thanks for your fast response!
I forgot to say a couple of things in my last message:
1. The hardware works fine under Win98, so I believe that the modem functions and that the phone line is clean.
2. The LAN behavior of the card is just dandy. I can pull about 820k/sec on my local ethernet, which is roughly competitive with the other machines around here.
3. I am using a PPP connection. Here is the behavior I observe: I log on. All is well. Under light load it performs as I would expect. As soon as I do something which saturates the channel (i.e., download a large file), after receipt of about 60-100k the download quits. If I watch the pretty graphs that is made by RedHat's usernet window, I can see the load climb up to full throughput (about 3k/sec) and then suddently drop off. This is followed by some pings at regular intervals. If I cancel the download (but remain connected) and begin again, I observe the same behavior.
I will experiment with the interrupts as you suggest.
Thanks very much for your help,
Incidentally, I'd like to purchase a Cardbus 100bT network card. Which seems is the most favourable for the pcmcia package these days?