Have you looked to see what the session is waiting for?

Here are a couple of queries that may help (need to provide the sid)

col minutes for 999.999
select event, total_waits, (time_waited/100)/60 Minutes, average_wait, max_wait
from v$session_event
where sid = &sid
AND event NOT LIKE 'SQL*Net%'
/


SELECT sw.sid, s.username, sw.event, sw.wait_time,
sw.state, sw.seconds_in_wait SEC_IN_WAIT
FROM v$session s, v$session_wait sw
WHERE s.username IS NOT NULL
AND sw.sid = s.sid
AND sw.event NOT LIKE '%SQL*Net%'
/


HTH,
Jodie