Jerry,
I want to make sure I understand what you think the expected behavior should be.
For example, selecting the quarter note would set snap to quarter notes, and allow quarter notes to only be inserted exactly on beats 1, 2, 3 or 4 (assuming 4/4 time signature.) Is that what you are expecting?
Wouldn't this mean it would be impossible to enter the quarter note on the "and" of any beat unless snap was disabled? Syncopation would be much more difficult!
Perhaps what you really want is to be able to set the snap (separately from the note value) to the smallest value you will need for the time being. A snap default of 32nd notes allows a lot of flexibility (unless you need 64th notes), but requires the user to be very accurate when placing the notes, so I can see how most of the time it would be better to be able to set the snap at eighth or sixteenth notes, or whatever is appropriate at the moment.