Integer fields can't be empty. They are always at least 0. We do not consider 0 as empty. Only "" (empty string) or NULL are classified as empty. You can override this display logic using layouts. Example as follows.
Code:
[cb:if value>"0"][value][/cb:if]
We'll probably make this a toggle parameter in the future. The reason for this is there are very valid reasons for why a 0 should be displayed and would break all of those usages if we considered 0 as empty.
krileon
