Resolution: Works As Intended
Affects Version/s: Minecraft 14w29b
Fix Version/s: None
Since I've upgraded my world from 28b to 29b I had to replace this_
/particle dripLava ~ ~ ~ 0.1 0.1 0.1 1 10 @a[score_OnGround=0,m=2]
/execute @a[score_OnGround=0,m=2] ~ ~ ~ /particle dripLava ~ ~ ~ 0.1 0.1 0.1 1 10
in order for it to work.
Thi happens because the particles are positioned relative to the commandblock instead of being relative to the targeted entity.
Hope you can replicate