Error of using Sort function

I try to use the Sort function (located in the ArcToolbox->Data Management Tools ->General) to sort a table for its specific field,, but had an error as follows:
If the sorted table is saved under the default ArcGIS folder under C:\Users\xxx\Documents\ArcGIS\Ddefault.gdb\, the Sort function works fine. But if I save the output file in the same folder of the input table (or anywhere else), an error occurs and the Sort function does not execute.
Any suggestions to fix the problem. I used ArcGIS 10.1. Thanks.