Before v8.0 of the SalesLogix web client, it used to be that you could define for a given picklist control on a screen whether or not the picklist input allows free form input or not (text does not need to match). This is a property attribute of the web control on the form it resides on.
You could also define the “Text must match a list item” attribute for a given picklist list; but that would only override the control level definitions on a smart part if the “Apply options to Web pick list” attribute at the picklist was also checked. That appears to no longer be the case.
Now if the picklist has the “Text must match a list item” attribute defined it overrides the control level definitions. So a picklist with that attribute can not have a picklist control on a particular screen that allows the user to input new data.
I have reported this issue to Swiftpage and they have registered it as a defect but no details have been given for a fix.