Lengthen sample sounds

Having trouble with LMMS? Ask about it here.
When i'm using the piano roll to compose a melody, the higher the pitch of a note, the shorter the note is in length. I know this is a normal occurrence but i was wondering if there's a away to tweak this so that the higher notes can draw out for longer. I'm finding this to be quite a handicap when i want to use a wide range within one piece.
unfourtunately not -there is a LADSPA plugin (TAP pitch shifter) that is meant to do that, but it only works for one note.. (eg useless for music-notes ), and it distort rather significantly
-can be used for long sampled vocals

Br.
Ive been searching for a solution to this problem too but I realised there is none. The only way to fix this problem is to work around it, I use audacity and use the pitch change effect which changes the pitch without changing the tempo.....its a very long process but its all there is atm.