Update to my post re: Asus GX D1081:
I may have been too quick to justify the above switch as the cause. What I didn't mention was that the switch was also connected to a 100Mb Router which was connected to an internet modem. Since this was at the end of the chain I didn't feel it relavent.(sp)
After the success with the one cable between 2 pc's I put an Asus switch between the 2 PCs. I detected no problem although I only tested for about an hour.
I started adding back all of my PCs and my other switch and still I was click free.
When I hooked of the 100mb router to the switch the clicks and pops started to occur.
Not sure what this means at this point as there are still variables I've yet to think of.
Jumbo Frames are set in the Network Card. I'm no expert but it is usually disabled at default. Once enabled, I believe both cards must have the same size of frame to work. (Which is selectable in Properties (Win).
DS