Workflow states and "Limit list to selected items"

Hello! I am creating an exposed filter by using states from the "Workflow" module. Specifically, I have two workflows, with a bunch of states in each. Only one of the two is associated with the node type I am manipulating in my view.

In order to create a filter that only contains the states that are relevant to my node type, I use "Limit list to selected items" and select only the states of the one workflow I need.

In the resulting popup menu of the exposed filter, however, an additional empty optgroup is generated for the other unwanted workflow, despite the fact that nothing was selected in there. The select looks like:

<select ..> <option ..>Any</option> <optgroup label="good states">
<option>one</option><option>two</option> <option>three</option>
</optgroup> <optgroup label="unwanted"></optgroup></select>

The second optgroup shouldn't be there; it also cannot be hidden in IE, as it doesn't implement "display:none" correctly on optgroup elements.

Thanks!