error modifying max_connections (maybe a little o.t.)

hi

i've recently began to test a java application with multiple
simultaneous users, and began to get a "java.sql.SQLException: FATAL 1:
  Sorry, too many clients already", so i figured out the problem could
be solved changing the max_connections parameter in postgresql.conf from
32 to a bigger number, say 64, but when restarting postgresql it fails, in
/var/log/messages all i can see is a "$Starting postgresql service:  failed"

i've tried to search in the pgsql list archives, but the i can't get the
  search resuylt page due to a timeout (maybe mi isp connection :( )

i'm using redhat 6.2 and postgresql 7.2-1PGDG

thanks in advance and best regards