Nando m8... Do what DSp tolled ya... I think U got it wrong...
device pannel, device setting, vst multitracking, in the asio/ sound card definition click in expert .. now just choose audio priority LOW!!

After midi run everthing back 2 audio, go back and change the priority 2 Very High ! ;)

Also remember 2 put all yer midi parts 2 the top of the arrangement.... the further 2 the top they r the best timming they have... (but this u probably new already)...

Steinberg midi interfaces use LTB which coupe with this a lot better...

I like using the delay setting 4 each part 2 get a really solid timming and some groove going :)

just some thoughs,

Z