Soapbox "caches" the values of picklists, so it doesn't have to run a query every time a page with a picklist is loaded.
The downside of this, is that sometimes you can make a change on the Saleforce side by adding or removing a Picklist value - and you won't see it on the Soapbox side right away.
Steps to resolve this are:
2) If that doesn't work, then:
a) Open the form and, and the click the item in question to edit it.
b) Save the item.
3) If that doesn't work, then:
a) Open the item and make note of all of its settings
b) Delete the item
c) Add the item as it was, replicating all the settings noted in 3a above
One of the above steps should get your picklist item appearing as expectec.