Jim,

I agree with some others that your problem most likely includes a coax cable / connector / terminator problem. A number of years ago when I worked technical support for a large pc manufacturer, we had about 20 pcs connect with coax. What a nightmare! If you decide to keep it, remember that when troubleshooting, the first thing is to reduce the size of the network to isolate the problem. In your case, since you only have 3 pcs, remove one from the physical network connection to isolate cable/connector/terminator problems.

Others have suggested going to twisted pair. I agree, especially with how 100Mb pricing has dropped, including hubs. Your potential for hardware problems with drop to almost zero, along with your mean-time-to-migraine.

Regards,
Marc Mandel