I might just be able to explain the crap resolution
There are four signals on the connector which are to do with detecting the capabilities of the monitor. If the "Monitor ID x" lines don't get through the switch correctly because the designers got lazy (oh how could that happen!), then the computer on the other side is unaware of what type of monitor is present and may end up defaulting to the bog standard resolution because that is the only resolution that it knows all monitors understand despite the fact that most of then will do a minimum of 1024x768 these days. I have the same issue with a Sun Sparc system and a high-end KVM I got off of fleabay on the cheap.

But then KVM's do have a tendancy to be a bit crap anyways. They'll do the job, but there will always be something they don't quite do right.
(An eejit passing by in a purple satin skirt with sparkly bits, Mon 3 Oct 2011, 17:20, Reply)