Items Maps don't always hold. Is it just me?

I am not 100% sure, but I have double checked a couple of items maps I have, especially for weather, and I sometimes see them displayed on the HabPanel and in the log as “sunny-day” instead of the mapped “Sunny” value.

I double checked with the maintainer of the HabPanel, and he mentioned that the panel was just getting the items from the engine, and he wasn’t doing any further changes.

Is this a known problem? Have people looked at it?