Ok Bayley, I was able to fix this so it more accurately plays the note lengths properly. This was attributed to a rounding issue. Notes were being turned on/off right at the resolution mark. Basically given the BPM of the file (which most players are inaccurately calculating) the note lengths were 23ms. Then turned on again at 24ms. With a 21ms resolution on the main event timer, this was causing a short delay in the note being turned back on appropriately. The new version does a much better job handling this.
One thing to note, The two free MIDI players referenced in the kit do not seem to use the correct BPM properly in playback. Play the MIDI file with Windows Media player, which plays according to the correct BPM of the file. This will have a slightly higher playback speed than the two free tools which appear to default/force 120BPM. This file is 140BPM. My player also correctly calculates BPM so it will play at the same speed that Windows Media Player does.
If you prefer the slower 120BPM playback, you can load the file in the Midi Editor program, then edit the Temp/BPM.
Even after changing this value you will notice that the Midi Editor player doesn't honor its value and the tempo will remain fixed. However the tempo difference will be reflected when played in MidiTesla or Windows Media.
I have also added 'Loop' to the software.
And sorry, sadly no Mac version at this time.
You can
download here, or from the fixed link at the top.