This is a problem that seems to be unique to the KM popup menu control, as I've never observed it in any other app. Perhaps @peternlewis can explain.
Yes, it is a subtlety that KM uses in several of its comparison methods:
- Use "
is" to compare strings (characters) - Use "
is =" to compare numbers
This is also the case with the other comparison operators:

Unfortunately, I can't find anywhere in the KM Wiki where this is documented.
@peternlewis, we need to update the wiki.
That is certainly a valid method and may be preferred by those that like palettes.
The disadvantage, IMO, is that now you have a separate Macro to maintain for each of the choices. This leads to duplicate code (Actions) and can allow unintended errors to creep in.
@ronald, to give you, and others, a better view of the choices for using a pick list, I have just uploaded this tutorial macro. I hope it will help all better understand the choices, and to pick the best tool for the job at hand.
MACRO: Methods to Pick from a List [Tutorial]
If you, or anyone, has questions about these methods, please post in that thread.