Maybe add one or more of the following values, which add to the wierdness?!

[Morris Johns]

'0X0'
'1E0'
1E-1111
['Infinity']

'0X0' : string that is hex for zero if converted to Number
'1E0' : Exponential notation for one if converted to Number
1e-1111 : underflow (zero)
['Infinity'] : ['Infinity'] == Infinity

PS: Thanks for the grid, it is a great reminder of the evils of ==.

PPS: Not to mention 077 versus 088 (ouch - octal!).

PPPS: An == or === symbol inside the green cells of the grids made it clearer to me (using developer toolbar).