Sorting before continuing

I am interested in sorting via an attribute before running my script. Currently I am trying to use an update cursor:

arcpy.gp.UpdateCursor (in_dataset,"","","", "attribute D")

It does not appear to work when I use the next search cursor. I sort as above then call the next line, check the fid and it is still 0. I tried to refresh in an attempt to make the sort stick but as of yet it has not worked.

Do I have to use "Sort_management"? I would like to complete the operation without creating a new .shp. It seems that the lock Sort_management puts on the file prevents it from writing over its self.

Thanks!