Struggling with pgBouncer

Question

I've got Postgres 9.2 and PgBouncer (The version that came with the 'stack builder'). I have a .net application connecting via Npgsql version 2.0.12 on a win7 machine.

My application can happily connect straight to the postgres server, but always fails to connect via the pgbouncer.

My connection string to npgsql (after some substitution is)

Sslmode=Prefer;Timeout=40;Server={0};Port={3};User Id={4};Password={1};Database={2};Pooling=False;

(I've also tried to connect to PgBounce with Protocol=3 explicitly and that didn't work.)

The database line from pgBounce ini is:

[databases]
something = host=localhost port=5433 dbname=somethingelse user=someone password=aaa

and in the userlist.txt I have "someone" "aaa" as required.

When my app runs the npgsql says "connection forcibly closed" and the pgbouncer error log says:

2013-02-06 20:16:57.594 2444 LOG File descriptor limit: -1 (H:-1), max_client_conn: 1000, max fds possible: 1030
2013-02-06 20:16:57.649 2444 LOG listening on ::/6433
2013-02-06 20:16:57.657 2444 LOG listening on 0.0.0.0:6433
2013-02-06 20:16:57.659 2444 LOG process up: pgbouncer 1.5.2, libevent 2.0.19-stable (win32), adns: evdns2
2013-02-06 20:17:22.066 2444 LOG C-01819410: something/someone@fe80::997b:396e:eacc:dd2b:3013 login attempt: db=somethingelse user=someone
2013-02-06 20:17:22.130 2444 LOG S-01836648: something/someone@127.0.0.1:5433 new connection to server
2013-02-06 20:17:24.069 2444 LOG C-01819410: something/someone@fe80::997b:396e:eacc:dd2b:3013 closing because: client close request (age=2)
2013-02-06 20:17:26.319 2444 LOG C-01819410: (nodb)/(nouser)@fe80::997b:396e:eacc:dd2b:3023 closing because: bad packet header (age=0)
2013-02-06 20:17:26.322 2444 WARNING C-01819410: (nodb)/(nouser)@fe80::997b:396e:eacc:dd2b:3023 Pooler Error: bad packet header

The npgsql exception says: (from a log file in app, the topmost exception follows down the nested exceptions):

Exception message:  Unable to read data from the transport connection: An established connection was aborted by the software in your host machine.
Exception source:  Npgsql
Exception stacktrace:     at Npgsql.NpgsqlClosedState.Open(NpgsqlConnector context) in Z:\Projectdirectory\Npgsql2.0.12.0.src\src\Npgsql\NpgsqlClosedState.cs:line 232
at Npgsql.NpgsqlConnector.Open() in Z:\Projectdirectory\Npgsql2.0.12.0.src\src\Npgsql\NpgsqlConnector.cs:line 695
at Npgsql.NpgsqlConnectorPool.GetNonPooledConnector(NpgsqlConnection Connection) in Z:\Projectdirectory\Npgsql2.0.12.0.src\src\Npgsql\NpgsqlConnectorPool.cs:line 346
at Npgsql.NpgsqlConnectorPool.RequestConnector(NpgsqlConnection Connection) in Z:\Projectdirectory\Npgsql2.0.12.0.src\src\Npgsql\NpgsqlConnectorPool.cs:line 185
at Npgsql.NpgsqlConnection.Open() in Z:\Projectdirectory\Npgsql2.0.12.0.src\src\Npgsql\NpgsqlConnection.cs:line 543
at *snip* the thing in my code that goes and opens the connection *snip*
-----------------------------------------------------
Exception message:  Unable to read data from the transport connection: An established connection was aborted by the software in your host machine.
Exception source:  System
Exception stacktrace:     at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
at System.IO.Stream.ReadByte()
at Npgsql.NpgsqlClosedState.Open(NpgsqlConnector context) in Z:\Projectdirectory\Npgsql2.0.12.0.src\src\Npgsql\NpgsqlClosedState.cs:line 184
-----------------------------------------------------
Exception message:  An established connection was aborted by the software in your host machine
Exception source:  System
Exception stacktrace:     at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)

Also, window firewall is off and anti virus I turned off temporarily.

The HBA conf file for postgres has:

host    all             all             127.0.0.1/32            md5
host    all             all           192.168.0.1/16            md5
# IPv6 local connections:
host    all             all             ::1/128                 md5
host    all             all         fe80::1/16                  md5

I've googled around and found no solution. Help! Thanks.

Peter.