Hi

First you need to read these two articles from BIAB about what the latency adjustments in BIAB do, or more importantly does not do as far as midi latency is concerned.

Quote from the following link
17. Why is there a delay between when I play a note on my MIDI keyboard, and when I hear the note play through my computer speakers?
You are most likely using a software synthesizer such as the Microsoft GS Wavetable or the Roland VSC as your MIDI output device. One characteristic of a software synth is that it takes some time for it to express the MIDI data it receives as sound. In other words, there is a delay between when a note is sent by Band-in-a-Box® (and other MIDI software) and when you hear the note played. This delay is called latency, and is normally a fraction of a second.
In Band-in-a-Box®, the Driver Latency setting in the Opt. | MIDI/Audio Driver Setup dialog is used to delay the notation and chord highlighting so that it is synchronized with the music during playback.

However, note that this is only a visual setting; it doesn't change the actual latency of the driver. There will still be a delay between when you strike a key on your keyboard and when you hear the note played.

For recording or playing live from an external MIDI synth, the solution is to use a MIDI Output Driver with no noticeable latency. This could be the built-in MIDI synth on your computer's internal sound card, or your external MIDI keyboard or sound module. If you prefer the sound quality of the soft synth, you can record using a no-latency driver, and switch back to the soft synth for playback when you have finished recording.

Link http://www.pgmusic.com/techfaq23.htm#latency

Also read this very informative
.
http://www.pgmusic.com/tutorial_bbwlatency.htm

Hope this helps a bit
Mike

BIAB2021 UltraPlus,AsusN55S1Tbssd, W10/64,Akai EIEpro
Yamaha CVP405,SquireStrat, CoolsoftVMidSynth
Novatation Impulse61 Ctr kbd, Cwalk blab Kontakt

http://mikesmusic.byethost16.com/