I suggest to remove Mondrian from the squeak-dev & -web images, it allows expressions at development time which are bugs at production time.
Examples: 3 + 4 value: 7 3 @ 4 x: 7
I have no idea why Mondrian is in Squeak-Dev, however these 'dangerous' class extensions are just a two click refactoring away:
1. Open Environment | Package: Mondrian 2. Method Refactoring | Rename Method: #value:/x:/y:
Done in Mondrian-lr.46 (+ a few oder fixes).
Lukas