Why is there a file named
   ftp://index.storsys.ibm.com/adsm/fixes/v1r2/netware/ip20396.3d1
that has 0 bytes?

The associated readme file says:

* ADSM Netware Client v1.2.0.8 (Fix IP20396) Install Instructions
*
*
* An image of a 3.5in 1.44M diskette is provided.  In order
* to use this image, you must ftp the loaddskf.exe program from this
* machine.  The loaddskf.exe program can be found in the
/adsm/tools/loaddskf
* directory.  You must download the loaddskf.exe program in binary!
*
*
* 1) Put a formatted 1.44 meg 3.5 diskette into your A: drive. Download
*    the IP20396.3D1 file to your workstation in binary.
*
*
* 2) Type "LOADDSKF IP20396.3D1 A: /f"
*
*
* 3) Put the installation diskette into the NetWare server's A: drive.
*    Then load the installation program by typing "LOAD A:INSTDSM".
*




Mark Keintz                            University of Pennsylvania / 6298
Computer Core Director                 Population Studies Center
mark_keintz AT pop.upenn DOT edu              3718 Locust Walk
phone: 215/898-6713  fax: 898-2124     Philadelphia, PA 19104-6298