This link could be helpful:
Slow session time:
Maybe you have to update your statistics.
One known limitation with Oracle 10g (10.2.0.1):
ORA-1445: ANSI joins may fail. Can occur for ANSI join queries with large views / subqueries.
Max. 6 joins are allowed
Max. number of fields in the querry (exact value unknown).
Solution: Update to a higher version.