Sorry - I don't have a remote here where I do this....try it now, think that should do it. By default it focusses on the play video button...and then any nav should just cause it to swap between the two buttons.
Addons I wrote &/or maintain:
OzWeather (Australian BOM weather) | Check Previous Episode | Playback Resumer | Unpause Jumpback | XSqueezeDisplay | (Legacy - XSqueeze & XZen)
Sorry, no help w/out a *full debug log*.