Oracle Database Discussions

Hi
I faced some problems with O8(Release 8.0.5.0.0) object types.
Look at the following definition:

CREATE TYPE T_JMJX AS OBJECT( LBNO NUMBER(3),...);

CREATE TYPE LIST_JMJX AS TABLE of T_JMJX;

CREATE TABLE JXGC.JMJXJL
(JMJX LIST_JMJX,...)
NESTED TABLE JMJX STORE AS N_JMJXJL;

One day when I opened Schema Manager,I got a shock: TABLE JXGC.JMJXJL has four colunms with the same name !!
name schema datatype
JMJX none LIST_JMJX
JMJX none LIST_JMJX
JMJX none LIST_JMJX
JMJX JXGC LIST_JMJX
But in SQL*Plus I type 'decs JMJXJL',the column JMJX appears only once.
Other tables that has object type columns has the same problem.

This doesn't has any infection on my applications.
The real problem comes when one day I want to move the user JXGC to an other server.
Export was done successfully but has curious phenomenon:
Exporting NJMJXJL(the Nested Table)......19678 Exported
The number of rows Exported is about four times than the rows it should has.
When Imp80 goes to the tables that have object type columns ,I got the following errors:
Importing Table JMJXJL ........
IMP-00009: abnormal end of export file
Import terminated successfully with warnings.

Please help me to solve this problem.Thanks a lot!