schwancr wrote:The work server is denying access because it recognizes that it already received these WUs.
This could be a client issue. Bruce has this phenomenon been reported before?
Yes, but it's not a common situation. I know of a couple of scenarios (and, of course, there's always the possibility of another scenario).
1) If a donor believes a WU has been submitted but it has not been credited, they sometimes restore a backup and attempt to get the client to send the WU again. For some donors who watch the credits very closely, even a short delay in crediting can induce them to try this method, particularly if the points are less than the donor expects.
2) If the donor adds a new client by copying the client's files to a new location, both clients can complete the active WU -- and of course only one of will get credit for it. Additional complications can arise if the UserID/MachineID settings are duplicated such as when Norton Ghost is used to clone a system.
3) Even if the donor does nothing, sometimes a WU is accepted by the server but message from the server to the client confirming the WU has been accepted gets "lost." The messages in the client's log say it was not uploaded and the results are left for the client to keep retrying to upload. This happens more frequently with certain types of proxies than when the client is not connected through a proxy, but it also seems to happen occasionally on any connection.