For a while now, I had an issue with the ATEN KVM switch (dual-DVI) when switching between my Windows and Mac systems. One of the monitors would almost always not be detected after switching. Sometimes this also happened after restarting my computer. The solution would be to turn off the PC and restart, and I would keep my fingers crossed that the second monitor would now be detected.

What I should have done is checked the ATEN website. They have a firmware upgrade for my particular switch. The only problem I had with the upgrade was finding a system with a serial port (I still don’t understand why ATEN would build a dual DVI KVM swicth with an upgrade cable that only connects to a serial port). After finding a Thinkpad notebook with a P3 inside and Windows 98 (it stil worked!), I did the upgrade.  Since the upgrade, I have not had the issue come up again.