CCK Check boxes not storing data

I've set up a couple of single CCK check boxes on a content type, with integer (or decimal) values.

Problem 1, the value is not stored in the database (field still 'null').

I can get around the problem by replacing both boxes by a multiple value checkbox. This works OK, but sets up yet another database table to search, which I'd rather not do.

Problem 2 is that single checkboxes do not display their labels at all, as far as I can tell, whether they are integer, decimal or text.

Am I missing something obvious here? It seems such an obvious bug that lots of people would run into it, yet I see no reference to anyone else having problems.