I can use the pan knobs only if i use the wheel on the mouse, but as soon as I left click on the knob and try to move it around with the mouse it just goes to 100% R and stays there. Another workaround is to open the track I/O and adjust the pan there. Its been like this since i swithced to Windows 8 prof (64 bit) almost a year ago. I have the 64 bit version of Reaper.
[4.611] panning problem
Linear Mode
