I found a similar bug in the BMax IDE for Linux, the bug is in the 1.30 IDE and in Seb's new builds. I never mentioned it because it's a low priority bug and because a random bug like that is only going to waste Seb's time when he could be fixing a more serious bug.
Anyway, here is how I reproduce the bug.
In BMax IDE, close all tabs and then browse to "samples/aaronkoolen/AStar/Callback.bmx" this file has very little text in it so is less confusing. Now just close that file and reopen it and repeat until the syntax highlighting doesn't load, it shouldn't take more than 10 trys.
I also just tried opening from the Recent Files tab and also just using the keyboard shortcuts for everything and the bug still occurs.
Anyway, here is how I reproduce the bug.
In BMax IDE, close all tabs and then browse to "samples/aaronkoolen/AStar/Callback.bmx" this file has very little text in it so is less confusing. Now just close that file and reopen it and repeat until the syntax highlighting doesn't load, it shouldn't take more than 10 trys.
I also just tried opening from the Recent Files tab and also just using the keyboard shortcuts for everything and the bug still occurs.