Oracle Database Discussions

I'm getting the following error
ORA-01119: error in creating database file '/TST/DATA/RUN/T1/TRF/TRF_000.dbf'
ORA-27040: skgfrcre: create error, unable to create file
HP-UX Error: 2: No such file or directory

This is what I'm doing:
sqlplus system/sys_pwd @Sql/crtbs TABLESPACE_TRF /TST/DATA/RUN/T1/TRF/TRF_000.dbf 40M "UNIFORM SIZE" 1M

where crtbs.sql script is:
-- 4 Parameter could be assume value "AUTOALLOCATE" or "UNIFORM SIZE"
-- 5 Parameter must assume a value only if 4 parameter is "UNIFORM SIZE"

create tablespace &&1
datafile '&&2' size &&3
EXTENT MANAGEMENT LOCAL &&4 &&5
/
exit

But this is the output:
old 1: create tablespace &&1
new 1: create tablespace TABLESPACE_TRF
old 2: datafile '&&2' size &&3
new 2: datafile '/TST/DATA/RUN/T1/TRF/TRF_000.dbf' size 40M
old 3: EXTENT MANAGEMENT LOCAL &&4 &&5
new 3: EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M

create tablespace TABLESPACE_TRF
*
ERROR at line 1:
ORA-01119: error in creating database file '/TST/DATA/RUN/T1/TRF/TRF_000.dbf'
ORA-27040: skgfrcre: create error, unable to create file
HP-UX Error: 2: No such file or directory

If I issue the same command in a SYSTEM session (user connected with system/sys_pwd) I obtain the same result:
SQL> show user
USER is "SYSTEM"
SQL> create tablespace TABLESPACE_TRF datafile '/TST/DATA/RUN/T1/TRF/TRF_000.dbf' size 40M EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M;
create tablespace TABLESPACE_TRF
*
ERROR at line 1:
ORA-01119: error in creating database file '/TST/DATA/RUN/T1/TRF/TRF_000.dbf'
ORA-27040: skgfrcre: create error, unable to create file
HP-UX Error: 2: No such file or directory

If I connect as sysdba the same command works:
SQL> connect / as sysdba;
Connected.
SQL> show user
USER is "SYS"
SQL> create tablespace TABLESPACE_TRF datafile '/TST/DATA/RUN/T1/TRF/TRF_000.dbf' size 40M EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M;

Tablespace created.

This is the ls command
(pluto)oracle9i>ls -lart /TST/DATA/RUN/T1/TRF/
total 4
drwxr-xr-x 3 oracle9i oinstall 512 Nov 23 10:57 ..
drwxr-xr-x 2 oracle9i oinstall 512 Nov 23 12:26 .


Why I'm not able to successfully issue that command while I'm system/sys_pwd ??!!??

Can you help me to solve this problem ??
Really thank you...
Marco