I have a import/export problem here. I exported a user(PROD1) using system user in Server A. When I import that user into Server B I got the following error. Have tried to increase the import buffer to 200,000 but still the same.

. . importing table "TB_MACHINE1"
IMP-00020: long column too large for column buffer size (22)
IMP-00028: partial import of previous table rolled back: 45580 rows rolled back
. . importing table "TB_MACHINE2"
IMP-00009: abnormal end of export file
Import terminated successfully with warnings.

Then I export the user(PROD1) using prod1 user in Server A. When I import the user into Server B this time got no error? How come? I have tried many times. Why the error comes out when I use system to export the user? Any idea? Tks.