The Apple System Profiler sees the UMAX Astra 4000U scanner as follows:
We recently got in the new 2.0GHz DP G5s. For this reason we cannot support this scanner (that means: nobody can under OS-X). This seem to be due to the interface construction fo the scanner.
We regret to say that the Umax 4000U scanner hardware is not recognized by the Apple System Profiler.