It looks very much like the installer is just a copy of the old beta
version. I already suspected that by seeing that the files have exactly
the same size, but after downloading the new package, it is obviously
the same as the old one:
  md5sum -b Csound5.01-win-d.exe
  71e0086091ce2ede117be23c4f003c5b *Csound5.01-win-d.exe
  md5sum -b Csound5.01b-win32.exe
  71e0086091ce2ede117be23c4f003c5b *Csound5.01b-win32.exe
By the way, is the old beta expected to be deleted ? It is somewhat
confusing to have it listed as the first file under Csound 5.01 release.
Also, is the new release built from the tagged 5.01 sources, or the
latest beta from CVS ?