angularjs filter of a select with empty value

I have a problem with a filter in AngularJS. See my code here: http://jsfiddle.net/sqev9/7/

I have a select that uses a filter in the ng-options field:

ng-options="listitem as listitem.Name for listitem in MyList.Items|filter:FilterList"

I also use an empty option because this select is optional.

As ng-model for the select I use the value "SelectedInList"

The problem is now that when the filter doesn't match anything, the "SelectedInList" variable in my $scope is not null then.

Simulate this by selecting "item1" and pressing "Go": the SelectedInList is now correctly the item1 object. Now the filter changes and the list is "empty": only the "-" item is there, which is also expected. Now pressing "go" again should give me "null" as SelectedInList, but it is still the item1 object, which I don't expect.

Any solutions to this approach?

Best regards, Tom,