First issue - maudio drivers are resource hungry (mine's got more latency than the built in sound card). Yours more than most because you've got midi and audio in the same device. Get more memory. 1.2gig isn't a lot these days.
Secondly reduce, not increase, the buffers to get the latency down.
Third, don't know whether the Ozone drivers allow this, but if you can reduce the sampling frequency. If you've got 24bit sampling, reduce to 16.
Lastly, as already said, make sure you're using usb2.