Hi, sema. I installed Jazz-Plugin v1.4 and using Mac OSX 10.9.5, Safari 7.1.2, Chrome 40, but I can't play 'G3' with 'B2'.
'G#3' with 'B2' is OK, 'Gb3' with 'B2' is OK too. When I press 'G3' with 'B2', both notes don't sound.
As you fixed similar bug, it might be a bug in the plugin. Isn't there still similar bug?
I've made many programs with Jazz-Plugin. I cheer Jazz-Plugin very much!