Tor-Bridge: DirPort unreachable

[Gitano <ran6oony7r9deku5@xxxxxxxxxxxxxx>]

Hi,

starting my Tor-Server as a bridge (with a clean /var/lib/tor/) I get:

Dec 28 20:06:03.406 [notice] Tor 0.2.1.9-alpha (r17777) opening log file.
Dec 28 20:26:07.562 [warn] Your server (87.122.2.241:9030) has not
managed to confirm that its DirPort is reachable. Please check your
firewalls, ports, address, /etc/hosts file, etc.

The debug.log shows:
###
Dec 28 19:43:23.953 [notice] Now checking whether ORPort
87.122.2.241:443 and DirPort 87.122.2.241:9030 are reachable... (this
may take up to 20 minutes -- look for log messages indicating success)
Dec 28 19:43:23.960 [info] connection_ap_make_link(): Making internal
anonymized tunnel to 87.122.2.241:9030 ...
Dec 28 19:43:43.534 [debug] connection_dir_client_reached_eof():
Received response from directory server '87.122.2.241:9030': 404 "Not found"
Dec 28 19:43:43.534 [info] connection_dir_client_reached_eof(): Received
server info (size 0) from server '87.122.2.241:9030'
Dec 28 19:43:43.534 [info] connection_dir_client_reached_eof(): Received
http status code 404 ("Not found") from server '87.122.2.241:9030' while
fetching "/tor/server/authority.z". I'll try again soon.
###

Starting my Tor-Server as a relay (# BridgeRelay 1), all works well:
###
Dec 28 19:33:32.091 [notice] Now checking whether ORPort
87.122.2.241:443 and DirPort 87.122.2.241:9030 are reachable... (this
may take up to 20 minutes -- look for log messages indicating success)
Dec 28 19:33:32.098 [info] connection_ap_make_link(): Making internal
anonymized tunnel to 87.122.2.241:9030 ...
Dec 28 19:33:53.771 [debug] connection_dir_client_reached_eof():
Received response from directory server '87.122.2.241:9030': 200 "OK"
Dec 28 19:33:53.771 [info] connection_dir_client_reached_eof(): Received
server info (size 1177) from server '87.122.2.241:9030'
###

Nothing else has been changed except 'BridgeRelay 1' and cleaning up
'/var/lib/tor/'!

Is it a bug? Can anyone confirm this behavior?

OS is Ubuntu 8.04 server.