pg_autovacuum

Hi,

I must be missing some obvious and trivial thing, since I simply can
get pg_autovacuum to work.

Im working on FC4, postgresql 8.0.6.
In the "postgresql.conf" file, I've set:

stats_row_level = true

I've restarted the postmaster. Yet, when I'm running pg_autovacuum, it says:

[2006-01-11 12:11:07 IST] ERROR:   GUC variable stats_row_level must be enabled.
[2006-01-11 12:11:07 IST]                 Please fix the problems and try again.

What more needs to be done ?

TIA,
Eran