you guys should fix it so that the filter is cleared properly when the UI is closed. The text that is typed in gets cleared, but the filter on the listview does not.
If you are struggling with this same issue, the hackfix is to simply clear the filter before dynamically modifying the value of your multiselect.
just make this call:
(multiSelect is your kendoMultiSelect instance object, ie: multiSelect = $('#myelement').data('kendoMultiSelect'); )