After 3 fresh downloads, it sounds like the ZIP archive containing the release 2.0-0637 for DS106e is corrupted. Here is the output from unzip:
error [m:/Temp/synology_powerpc_106e_0637.zip]: missing 8189 bytes in zipfile
(attempting to process anyway)
error [m:/Temp/synology_powerpc_106e_0637.zip]: attempt to seek before beginning of zipfile
(please check that you have transferred or created the zipfile in the
appropriate BINARY mode and that you have compiled UnZip properly)
(attempting to re-compensate)
Dispite the huge warning, a file is extracted. However, I won't update my DS106e with it... no trust !
UPDATE: zip file from mirror "HarryPotter Switzerland Mirror" is ok...