I've made a number of commits to MASON as we've been stress-testing it  
and finding minor bugs.  But one is a surprisingly major GUI bug that  
I am quite weirded out by since it went unnoticed for all these years:  
for fields where objects can be located at negative locations  
(continuous, sparsegrid, etc.) if you put an object at such a location  
and the grid resolution is fine enough, the object will not be able to  
be hit (or selected, or moved, or inspected) with the mouse.  Anyway,  
I did a bugfix there, but I am concerned my fix may tickle a bug in  
someone's code, so if you find something not working after doing an  
update, please let me know.