It may be trying to fill the queue. If it is downloading wu's wait for that to stop and then see if it sends in the completed wu's. If that is not the deal then you can cut the wu out and paste it in another folder. This should cause the others to send and then you can paste it back in and see if you can get it to send.
Not at my box now so I couldn't tell you off-hand where to find the wu's but as far as I remember the folders are self explanitory and you can desipher which result is which by the name I think.