Oracle Database Discussions

Hi, I'm using oracle 10.1.0.3 on Windows 2003 Server service pack1

Iin my alert log I've a lot of rows like this:

Wed Jan 14 08:45:31 2009
Errors in file d:\oracle\product\10.1.0\admin\ergon\udump\ergon_ora_564.trc:
ORA-07445: exception encountered: core dump [ACCESS_VIOLATION] [0x7C8224B2] [] [] [] []
ORA-07445: exception encountered: core dump [ACCESS_VIOLATION] [0x7C8224B2] [] [] [] []
ORA-07445: exception encountered: core dump [ACCESS_VIOLATION] [0x7C8224B2] [] [] [] []

I know that for errors like this I must check metalink so I went on ORA-600/ORA-7445 Troubleshooter but it ask me the failing function, if I insert ACCESS_VIOLATION it say that is not a valid failing function. In the help is said that sometimes is necessary "to look in the trace file for the Call Stack Trace and locate the first function that is not part of the error handling routines"

The strange thing is that in my trace file I don't have a valid call stack:

Dump file d:\oracle\product\10.1.0\admin\ergon\udump\ergon_ora_564.trc
Wed Jan 14 08:45:23 2009
ORACLE V10.1.0.3.0 - Production vsnsta=0
vsnsql=13 vsnxtr=3
*** 2009-01-14 08:45:23.439
ksedmp: internal or fatal error
ORA-07445: exception encountered: core dump [ACCESS_VIOLATION] [0x7C83248B] [] [] [] []
ORA-07445: exception encountered: core dump [ACCESS_VIOLATION] [0x7C83248B] [] [] [] []
Current SQL information unavailable - no session.
----- Call Stack Trace -----
calling call entry argument values in hex
location type point (? means dubious value)

Can you help me?
Thanks
Regards