This is almost certainly caused by the fact that you are using an emulation layer to run the windows program which isn't getting enough CPU time.
For realtime app's like this perhaps you should seriously consider using the windows app on a native windows machine or if you prefer try
Ubuntu Studio as it has been developed with a realtime kernel and the necessary native applications for what you are trying to do.
Let us know how you get on.
in my definition midi is an interface which controls midi instruments. It controls sound banks and numbers and the velocity length and pitch of notes to play. IN my case, the notes, which were composed, sound as if somebody completely drunk would play them. It's completely irregular and out of time.