[exim] exim + sql relay

anyone have any tips on using exim with sql relay?

i have a postgresql database on a nearby server, and
want to use sql relay to pool connections. sql relay
is installed on the mail server alongside exim. the
exim version is 4.66, underlying OS is fedora core 5.
postgresql is 8.1.mumble, whatever is current for fc5.

i've tried the following:

1) pointing exim at the socket i specified in sqlrelay.conf:

     hide pgsql_servers = \
      (/tmp/munged.socket)/munged/mungedmail/mungedpassword

    exim tries to open /tmp/.s.PGSQL.0 anyway and fails (noone
    is listening to that socket).

2) compiling exim against the sql relay client libs instead
    of the postgresql client libs. compilation succeeds but
    exim crashes with a seg fault instantly.

3) using LD_PRELOAD before launching exim daemon to substitute
    sql relay libs, OS declares this impossible and ignores the
    directive.

4) telling sql relay to bind to /tmp/.s.PGSQL.0 instead of
    /tmp/munged.socket, this appears to work at first, but
    hangs right after the debug output announces the new
    connection.

i'm going to try using a TCP/IP connection next, but i have
always been under the impression that unix sockets performed
better.

thanks in advance,
richard