I had a similar problem when I aligned the highback with the board, as it should be. The cable was not symmetric anymore and would pop out of the guide. Reduce the angle of the highback respect to the edge of the board until the cable stays put.
Another possibility is that the right side guide in your pic moved a bit, check that the screw is tightened and not moving. I see your right side cable attachment a bit high, there is a screw at the base of the ankle strap, make sure it is tight enough so that the cable attachment cannot rotate too much and go out of place.
Tighten the screws regulating the angle of the highback ( left and right, under the ankle straps attachments) make sure they are not loose letting the binding unaligned. They do loosen up.
There two small "bumps" for lack of a better term inside that piece that keep your cable aligned, forcing the cable to stay inside. Make sure that the cable is placed correctly in the first place. I am trying to replicate your issue on my binding...unsuccessfully.
Hope this helps!
2015/16 -17- Kirkwood days
Arbor A-Frame 158 2009-10
Jeremy Jones Hovercraft 156, 2011/12
Subaru WRX 06 - 181K
Last edited by KIRKRIDER; 02-17-2012 at 05:13 PM.