9i Agent and 10g Agent on the Same Host

OS: windows 2003
Database: 9.2.0.5

Currently, some problem happened when both 9i Agent and 10g Agent are running on the
same host. The database is configured in both OEM 9i and Grid Control 10g. The database
was originally monitored by OEM 9i. There was a backup job schedule inside OEM 9i.
After installing agent 10g and configuring the database under Grid Control 10g, the
new backup job inside Grid Control is fine. But the backup job inside OEM 9i stays
'started' status while the job is actually successfully executed. Rescheduling job in
OEM 9i can not always resolve the problem. The resule is random.

No idea about the reason!