Line 37 should be EntityBox masterblock,-1,-0.5,-0.5,2,1,1 not EntityBox masterblock,-1,-0.5,-0.5,2,10,1. Changing it doesn't fix the problem, though.
I couldn't see any issues with your code that would cause this problem, so I'm thinking its a Blitz bug with box collsions. Best I can suggest is that you post a bug report and switch to using polygonal collisions (which worked fine when I used them with your code).
EDIT: I'm using version 1.98. The problem occurred in this version, as you mentioned above.
I couldn't see any issues with your code that would cause this problem, so I'm thinking its a Blitz bug with box collsions. Best I can suggest is that you post a bug report and switch to using polygonal collisions (which worked fine when I used them with your code).
EDIT: I'm using version 1.98. The problem occurred in this version, as you mentioned above.