Debugging grayed out even pldebugger is installed in postgres

Hello,

I don't know why, but I am unable to use debugging feature in
pgAdminIII. Debugging selection in menu is still greyed out.

My environment is:

Linux Fedora 9, Postgres 8.4.0, PLpgSQL Debugger (latest CVS - version 1.11)
pgAdminIII 1.10.0 - Windows version

Debugger is installed in PostgreSQL, library plugin_debugger.so is
loaded and pldbgapi.sql script was used to create debug functions in
desired database. If I open database in PgAdminIII and look into
Funcions, debugging functions like ladbg_get_target_info or
pldbg_set_brakepoint are present and it looks that they are working,
because I am able to call them in SQL. But still debugging is not
available from menu. No debugging in context menu and debugging in
main menu is still greyed out.

I thought that there could be something wrong in so recent versions,
so I tried to compile PostgreSQL 8.3.7 from source with PlpgSQL 0.93,
but still no luck. Still no debugging in pgAdminIII.

Thanks,
Petr