We upgraded from 9i ( to 10g (

In 10g, the DB is doing Full Table Scans by the CONNECT BY START sql statements.

I have tried the following:
1) set "optimizer_features_enable"= '9.2.0' - did not help

2) set "optimizer_features_enable"= ''
and set "_optimizer_rownum_pred_based_fkr"= false
- did not help

and I got the following error:
ERROR at line 33:
ORA-00600: internal error code, arguments: [12426], [69], [], [], [], [], [], []

- did not help

In Metalink, I see that Oracle is aware that in 10g
there is a bug (BUG 5211863) Poor plan for Connect By.
The bug reports that in the bug will be resolved.
However does not have any release yet.

Did anyone encounter the same problem in 10g (
and find a solution (that the DB will not do Full Table Scans) ?