Float field select box - incorrect value selected on edit

We've created a float field (to display the number of bathrooms in apartments)
The edit field is a dropdown list, containing some values.

The value in the dropdown is saved OK, but if you try to re-edit the node, the field dropdown ALWAYS starts with the first value in the Allowed Values List (in our case, .75)

I thought it might be a string/float cast problem, so I set it up this way, and the dropdown functions PROPERLY:
.75|0.75
1|1.00
1.25|1.25
1.5|1.5
1.75|1.75
2|2.00
2.25|2.25
2.5|2.5
2.75|2.75

This is how we originally had the Allowed Values List set up, which gives the incorrect value.
0.75
1.00
1.25
1.50
1.75
2.00
2.25
2.50
2.75