I can't access the database

I'm running an intranet service with php and postgresql 6.5.3 (I KNOW
THIS IS AN OLD RELEASE) and the pgsql stopped responding.

I have runned vacuumdb --verbose on my database and I get the following
message:

NOTICE: --Relation master_en_curso--
NOTICE: Rel master_en_curso: TID 135/60: OID IS INVALID. TUPGONE 1.
NOTICE: Rel master_en_curso: TID 135/61: OID IS INVALID. TUPGONE 1.
NOTICE: Rel master_en_curso: TID 135/71: OID IS INVALID. TUPGONE 1.
NOTICE: Rel master_en_curso: TID 135/72: OID IS INVALID. TUPGONE 1.
NOTICE: Rel master_en_curso: TID 135/86: OID IS INVALID. TUPGONE 1.
NOTICE: Pages 6264: Changed 0, Reapped 3, Empty 1, New 0; Tup 579420:
Vac 57, Keep/VTL 526929/229347, Crash 52, UnUsed 2827, MinLen 57, MaxLen
94; Re-using: Free/Avail. Space 12793/137443881; EndEmpty/Avail. Pages
0/3. Elapsed 2/3 sec.
ERROR: failed to add item with len = 85 to page 137300014 (free space
137431088, nusd 2098, noff 2099)
vacuumdb: database vacuum failed on diamnet.

When I run it a second time the message is like this.
NOTICE: Index pk_master_mensajes: Pages 2; Tuples 51: Deleted 0.
Elapsed 0/0 sec.
NOTICE: --Relation master_en_curso--
NOTICE: Rel master_en_curso: TID 135/60: OID IS INVALID. TUPGONE 1.
NOTICE: Rel master_en_curso: TID 135/61: OID IS INVALID. TUPGONE 1.
NOTICE: Rel master_en_curso: TID 135/71: OID IS INVALID. TUPGONE 1.
NOTICE: Rel master_en_curso: TID 135/72: OID IS INVALID. TUPGONE 1.
NOTICE: Rel master_en_curso: TID 135/86: OID IS INVALID. TUPGONE 1.
NOTICE: PortalHeapMemoryFree: 0x82bf090 not in alloc set!
NOTICE: Pages 6264: Changed 0, Reapped 3, Empty 1, New 0; Tup 579420:
Vac 53, Keep/VTL 526929/229347, Crash 51, UnUsed 2831, MinLen 57, MaxLen
94; Re-using: Free/Avail. Space 8733/137439821; EndEmpty/Avail. Pages
0/3. Elapsed 72/3 sec.
pqReadData() -- backend closed the channel unexpectedly.
This probably means the backend terminated abnormally
before or while processing the request.
We have lost the connection to the backend, so further processing is
impossible. Terminating.
vacuumdb: database vacuum failed on diamnet.

I can't see the tables in the database or execute querys.
Anyone has a clue about this ?