I'd like to throw in some factual observations.
I had used a combination of Anker USB 3.0 4-Port Hub (previously had issue with trusty ol' Belkin USB 2.0 7-Port Hub too, that started to ware out after several years reliable PC use), Matrox DualHead2Go ME GXM, Two Samsung SyncMaster DVI-D monitors and an Apple A1243 2-Port Keyboard. Using various methods and port/load combinations, I was getting numerous problems as reported in this post. Not happy with three problems: intermittent drive disconnects, input device stutter/freezes, LAN disconnect.
Solution for me
Using my 2-Port Apple keyboard directly plugged into the lower-powered USB port on my Macbook, plug my mouse into that. Tried both wired Microsoft Comfort Optical Mouse 1000 (personal favourite of mine - have 3 or 4 of them) and/or Targus Wireless Mouse. These ports are down-stream only and provide stable input device connectivity and stability (supports the type of USB input device use as described by Apple).
I typically plug my Anker USB 3.0 Hub into the second Macbook USB port and plug my drives and GXM into that, but I am not confident with either drive or GXM stability (in multiple configurations). Instead, I have plugged a single USB drive directly into the second Macbook USB port, with a combination of connecting to other drives via LAN network. This proves stable, although I have to give up my external displays and/or multiple USB drives.
So now, to up my USB connectivity, I have ditched the external displays and GXM, and opted for a larger 27" Asus displayPort-connected monitor (with no USB Hub - to ensure no USB device conflict), so that I can permanently connect an external display without giving up a USB port. Still, using one physical drive plugged directly into a Macbook USB port as recommended by Apple, ironically.
On occasion however, I have switched into native Bootcamp and USB heaven opens up ... I can use the USB Hub exactly as I want, plus I don't get any of the issues that intermittently occur with the GXM. This confirms to me that the Macbook hardware is compatible with USB devices in Bootcamp, than it is with native OSX that USB connectivity is so hit-miss (the double irony for me too, is that my GXM is the Mac model, but it actually only works 100% in Windows Bootcamp rather than OSX - unless I use the latter setup without USB Hub to drive multiple USB drives).
This setup might be less than ideal, but it means I can have 100% stable connectivity and stability, with a bit of planning.
Hope this can prove a useful solution to sombody else.