I have a serious problem with hanging backends.

Hi,

I have a serious problem with hanging backends.
This is wat I get from ps ->
postgres 23507 22794  0 13:33 ?        00:00:09
/usr/local/pgsql/bin/postgres 1.1.3.123 postgres bts01 SELECT waiting


This blocks all the other clients.   (ODBC call failed)

The situation

-  PostgreSQL 6.4.2 on i686-pc-linux-gnu, compiled by gcc 2.7.2.
(SlackWare)
-  30  Access 2000 clients connecting through 6.40.00.06 ODBC driver

-   ODBC connections error's

        ->   CONN ERROR: func=SQLGetConnectOption,
    desc='fOption=30002', errnum=205, errmsg='Unknown connect
    option (Get)'

------------------------------------------------------------
                henv=144902176, conn=144863832, status=0,
    num_stmts=16
              so        ck=144902128, stmts=144902048, lobj_type=-999

----------------SocketInfo-------------------------------
             socket=-1, reverse=0, errornumber=0, errormsg='(NULL)'
             buffer_in=144870304, buffer_out=144874408
             buffer_filled_in=0, buffer_filled_out=0, buffer_read_in=0

              CONN ERROR: func=SQLSetConnectOption,
    desc='fOption=30002, vParam=143791720', errnum=205,
    errmsg='Unknown connect option (Set)'

------------------------------------------------------------
             henv=144902176, conn=144863832, status=0, num_stmts=16
               sock=144902128, stmts=144902048, lobj_type=-999

----------------SocketInfo-------------------------------
              socket=-1, reverse=0, errornumber=0, errormsg='(NULL)'
              buffer_in=144870304, buffer_out=144874408
              buffer_filled_in=0, buffer_filled_out=0,
    buffer_read_in=0

-  In de server-log I found that the access-application wants to
connect with the user Admin   then we get
    FATAL 1 : user Admin not in pg_shadow

    But in the connection properties the user postgres is set.
       This (connection with user Admin) seems to have started with
    the conversion 97 -> 2000

    I've added the user, this error was gone, but some of the jobs

    are admin owned other postgres

    -  I had problems before with the MaxBackendId
    I've rebuild with MaxBackendId set to 128  and started the
    postmaster with -B 256 parameter.
    This was because of the message "cache invalidation
    initialization failed"
      So this was solved, or is

-  In the loggings the SELECT waiting jobs hang on ProcessQuery and
the other InitPostgres fail.

- vacuum verbose analyze doen't seem to report errors

- debug higher then 4 is not usable (2 gig in 10 minutes)


In which direction do I have to search?
        Can there be data corruption without being reported?
        Can it be solved with a pg_dump file, destroydb, createdb,
    psql -e file ?  (Not done already -> production machine)
        Is our version to old -> should an upgrade help?
        .... ?

Thanks,

Jeroen Ryckeboer