error when using data pump import

 Hi,

 I'm getting error when impdp a database:

ORA-31626: job does not exist
ORA-31633: unable to create master table "user1.SYS_IMPORT_FULL_05"
ORA-06512: at "SYS.DBMS_SYS_ERROR", line 95
ORA-06512: at "SYS.KUPV$FT", line 980
ORA-01950: no privileges on tablespace 'USERS'

Here's the command I issued:

$ impdp user1/<password> DIRECTORY=dp_dir DUMPFILE=dpexpfull.dmp FULL=y LOGFILE=dpimpfull.log

user1 have sysdba role. Also I increased the USERS tablespace size from 5M  to 100M. Please help.

Thanks,