On Sat, Nov 14, 2009 at 6:29 PM, Kristopher Browne <kris.browne at gmail.com> wrote: > If the kvm isn't USB2, or if it was off-spec, it might not be fully > compatible with the keyboard. > > Generally if the 3 lights are on solid, it means its getting some juice, if > not plenty, but its not initializing right. Remember that I said the keyboard does work if plugged directly into the KVM, so it's compatible on that level at least; just not paired with the extension cable as well. One thing I'm pondering is that maybe it gets enough power, but too much lag. The USB spec mentions a maximum round-trip delay, which would be consistent with getting the three-lights behavior when I string five or more small extensions together. Quoth Wikipedia, "The maximum length of a standard USB cable (for USB 2.0 or earlier) is 5.0 metres (16.4 ft). The primary reason for this limit is the maximum allowed round-trip delay of about 1,500 ns. If USB host commands are unanswered by the USB device within the allowed time, the host considers the command lost. When adding USB device response time, delays from the maximum number of hubs added to the delays from connecting cables, the maximum acceptable delay per cable amounts to be 26 ns." If the KVM is slightly off or just not as smart as other things, that could exacerbate the problem so it appears sooner, and that answer would also match with adding powered hubs not helping. I did also just find out that there's such a thing as a "USB over Cat5 extender", which basically consists of two devices (one for each end) converting a USB type A connector to RJ-45, then lets you use Cat5 cable for the distance, allowing much longer distances. Do you think that might help? They run from $50-$120, which would be worth it to me if it actually works, but I don't want to go placing Newegg orders without having any idea if it's related to my problem.