dblink and hostname resolution problem

Hi list!

I am using DBLink on a Win32 system running PostgreSQL 8.2 to query a table on another similar system (Win32 /
PostgreSQL8.2). 
If I query the server with dblink('hostaddr=ip_address ...', ...), it works fine, but if I try to use the hostname
instead(dblink('hostaddr=myserver.mydomain.com ...', ...)), I have an error : 

ERROR:  could not establish connection
DETAIL:  could not translate host name "myserver.mydomain.com" to address: Unknown server error

Both server can resolve this address though.
Is this a known issue ? Is there something I can do about it ?

Thansk a lot !

Regards
--
Arnaud