pg_clog (?) problem with VACUMM

Hi all. Well, im having this problem for the first time.
When executing a VACUUM, i have this msg:
gse_new_version=# VACUUM ;
ERROR:  could not access status of transaction 118
DETAIL:  could not open file "pg_clog/0000": No existe el fichero o el 
directorio

Ok, wtf, i will create the file. So touch pg_clog/0000 and VACUUM again....
ERROR:  could not access status of transaction 118
DETAIL:  could not read from file "pg_clog/0000" at offset 0: Conseguido

I hope the error will still be clear due to the word "Conseguido", wich 
will be something like 'acomplished', or 'obtained'

The database was created making a "with template=gse" modifiers. 
Vacuuming the 'gse' database gives me no errors at all.

Here is the final lines from strace when triyng to vacuum...
lseek(20, 0, SEEK_SET)                  = 0
read(20, "", 8192)                      = 0
close(20)                               = 0
rt_sigprocmask(SIG_SETMASK, ~[QUIT ILL TRAP ABRT BUS FPE KILL SEGV CONT 
STOP SYS RTMIN RT_1], NULL, 8) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=377, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=377, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=377, ...}) = 0
write(2, "<2007-11-27 16:54:23 ART, gse_ne"..., 346) = 346
sendto(8, "E\0\0\0\240SERROR\0CXX000\0Mcould not ac"..., 161, 0, NULL, 
0) = 161
munmap(0x2aaabffa9000, 839680)          = 0
munmap(0x2aaabdfa8000, 33558528)        = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
sendto(7, "\4\0\0\0\310\3\0\0\1\0\0\0\2731\0\0 S\255\0\r\0\0\0+\0"..., 
968, 0, NULL, 0) = 968
sendto(7, "\4\0\0\0\310\3\0\0\1\0\0\0\2731\0\0 S\255\0\r\0\0\0\0\0"..., 
968, 0, NULL, 0) = 968
sendto(7, "\4\0\0\0\310\3\0\0\1\0\0\0\2731\0\0 S\255\0\r\0\0\0\0\0"..., 
968, 0, NULL, 0) = 968
sendto(7, "\4\0\0\0\310\3\0\0\1\0\0\0\2731\0\0 S\255\0\r\0\0\0\0\0"..., 
968, 0, NULL, 0) = 968
sendto(7, "\4\0\0\0\370\0\0\0\1\0\0\0\2731\0\0 S\255\0\3\0\0\0\0\0"..., 
248, 0, NULL, 0) = 248
sendto(7, "\4\0\0\0008\3\0\0\1\0\0\0\2731\0\0\0\0\0\0\v\0\0\0\0\0"..., 
824, 0, NULL, 0) = 824
sendto(7, "\3\0\0\0\27\0\0\0\1\0\0\0\2731\0\0<IDLE>\0", 23, 0, NULL, 0) = 23
sendto(8, "Z\0\0\0\5I", 6, 0, NULL, 0)  = 6
recvfrom(8,   

Dont know what to do now.
Wait...i have some more.
When vacuuming a table at a time, i got the table making vacuum crash. 
It's this one:
gse_new_version=# \d words            Table "public.words"   Column     |       Type        | Modifiers
---------------+-------------------+-----------page_id       | integer           |word          | character varying
|word_position| integer           |original_word | character varying |
 
Indexes:   "words_idx" btree (upper(word::text))   "words_page_id_idx" btree (page_id)
"words_page_id_word_position_id"btree (page_id, word_position) CLUSTER   "words_upper_idx" btree (upper(word::text)
varchar_pattern_ops)

Im souspiciuos about the CLUSTER (dont ask why :-). Meanwhile im looking 
for 'unclustering' tables and triyng again.

Server version: 8.1.2
On SuSE 9.1

Some other ideas will be apreciated.
Thanks!!

Gerardo.