Unable to Drio Materialized View log

Hi ,
I created a materialized view log which i am unable to drop and the documentation does not say anything about it.

I created the log as

SQL> create materialized view log on ofas with rowid;

Materialized view log created.

Now when I do a select * from tab it gives me

SQL> select * from tab;

TNAME TABTYPE CLUSTERID
------------------------------ ------- ----------
AVG_ACTUAL_US TABLE
COMPANY_LIST TABLE
MLOG$_OFAS TABLE
OFAS TABLE
PLAN_TABLE TABLE
TIME_LIST TABLE

The bold one being the log

I dropped it using the command

SQL> drop table MLOG$_OFAS;

Table dropped.

Now when I try to create it again, it gives me the error

SQL> create materialized view log on ofas with rowid ;
create materialized view log on ofas with rowid
*
ERROR at line 1:
ORA-12000: a snapshot log already exists on table 'OFAS'

Please Suggest.

btw is there anywhere i can get good info on materialized views. the documentation sucks

Thanks
Ronnie