I mapped my 2 extra mouse buttons to vials 1 and 2, and after doing that every time I open the Options menu, clicking ok causes the gui to become unresponsive (hitting the escape key instead avoids the hang). The mouse buttons do work as vials as expected, I just can't open the options menu without the workaround I figured out. In addition, the control config tab fails to show what keys are bound starting at wherever I bound the extra mouse button.

Steps to reproduce problem:
1. Bind one of the extra mouse buttons to something
2. Click Ok
3. Open the Options menu again

Workaround:
1. Close and relaunch spiral knights
2. Open options and restore the keybinds to Default
3. Click OK
4. Close and relaunch spiral knights

Other info:
The mouse in question is a Logitech G400, and I'm not using Logitech Drivers, just generic windows plug and play ones.
Web browsers map those buttons to Forward and Back
After binding the mouse button, the bound key still displays as "none", instead of changing to "X1B", or "mouse button 4" or whatever.

I have these buttons mapped in Torchlight 2, and this is what the keycodes are in the settings file, in relation to Left/Right/Middle click (not sure if this would be of help)

999 Left Click
1000 Right Click
1001 Middle Click
1002 X1B (extra mouse button 1)
1003 X2B (extra mouse button 2)


Pic of what the Control Config looks like:
http://i.imgur.com/boRyOwX.jpg

projectx.log
http://pastebin.com/M7d6e0LV