ok , thanks.
@Repetier :
there is another guy also with a delta fighting with this issue see Post :
<font size="4">"Laser turned on on all moves".</font>
i loaded configuration from this guy to dev version and checked on Mega/Ramps.so it does not switch off laser during g0 moves .no reaction to M5, laser gets switched on during any kind of move...changing from delta to cartesian it works as it should.Did crosstest on my due setup and in both versions(delta and cartesian)
Laser works as it should. might that be a memory problem on AVR Mega2560?any idea?