pgaccess.tcl

I have the following error message when I start pgaccess.tcl (while
opening a database):

>Error in startup script: First argument is not a valid query result
> while executing
>"pg_result $pgres -numTuples"
> (procedure "open_database" line 36)
> invoked from within
>"open_database"
> (procedure "main" line 12)
> invoked from within
>"main $argc $argv"
> (file "./pgaccess.tcl" line 5203)

I get a window with:
Tcl error executing pg_exec select relname from pg_class where
relname='pga_queries'
Invalid option pg_result result
?option?where?option is
-status
-conn
-assign
....

I am using postgresql-6.3.2 under Linux.
Thanks for your help.
--