Video transition "right to left" somtimes inverted

With a video on chanel 1 than a second on the channel 2, add a transition right to left -> OK (the arrow of the transition is going down)
With a video on chanel 2 than a second on the channel 1, add a transition right to left -> transition is in fact left to right (the arrow of the transition is going up)

With a video on chanel 1 than a second on the channel 2, add a transition left to right -> OK
With a video on chanel 2 than a second on the channel 1, add a transition left to right -> transition is in factright to left

System :
OpenShot 1.4.2, Ubuntu 11.10 64Bits