Sorry It is the same thing usually. In your software change the speed to double, then on your lcd or repetier turn the feedrate setting to 50%. I think that should clear it up.
I haven’t messed with the laser too much but if you can change the travel and the burn speed to the same. For example if your software trys too move faster when it isn’t burning it will trigger the acceleration limits, but if it never changes speed it should move smoother.
I could also be very wrong on all of this.
I am done for the night but if you want to zip the gcode and upload it here it might help to understand what is going on. I can look at it tomorrow.