RelationBuildDesc Notice

DB appears to be corrupted but cannot isolate cause, it has happened
multiple times after recreating database. The system seems stable otherwise

The message when trying to do
psql name_of_database:
NOTICE: RelationBuildDesc: can't open pg_statistic: No such file or
directory
ERROR: cannot open pg_statistic: No such file or directory

if I do a \d
The message is:
cannot open pg_statistic: No such file or directory

if I do a verbose vacuum, things go fine till the end....a sample:
NOTICE: RelationBuildDesc: can't open pg_group: No such file or directory
NOTICE: RelationBuildDesc: can't open pg_group_name_index: No such file or
directory
NOTICE: RelationBuildDesc: can't open pg_group_sysid_index: No such file or
directory
Error: _mdfd_getreInfd: cannot open relation pg_group: No such file or
director

if I do a REINDEX from a backend:
NOTICE: RelationBuildDesc: can't open pg_group: No such file or directory
NOTICE: RelationBuildDesc: can't open pg_inherits: No such file or
directory
NOTICE: RelationBuildDesc: can't open pg_inherits_rlid_seqno_index: No such
file or directory

Anyone know what the real issue is or how to fix?

Thanks,

TRH