leave request workflow ESS withdrawn

hi there,

we are using standard task TS12300097 for approving ESS leave requests from UWL.

so far, so good, BUT: in very rare situations (lets say 2 out of 1000 requests) the workitem has the status WITHDRAWN.

But in UWL it is only possible to approve or reject the workitem ! so normally there only should be status APPROVED or REJECTED

so how can a status WITHDRAWN happen ? The absence is booked in Infotype 2001, but the leave request has the wrong status, also in team calender it is shown in wrong status.

br, Martin