Upd: same problem when cloning my own repository.
<verbatim>
                Bytes      Cards  Artifacts     Deltas
Sent:              53          1          0          0
Received:         152          2          0          0
Sent:             648         26          0          0
processed: 0%         fossil: unknown command:
</verbatim>
Both server and client are running fossil [d0753799e4] 2010-11-01 14:23:35 UTC (Linux x86-64 version on server, Windows XP version on client).