Oracle Database Discussions

I am encountering a large and growing number of orphaned Oracle processes (show up in v$process but not in v$session).
The DB has hit the default 150 processes twice already (hanging the database), and then when I raised the processes to 300, it ran out of memory to allocate for process when it hit 233 (hanging the database yet again).

I just upgraded my databases from 10.2.0.1 to 10.2.0.3 (the problems began a couple of days later).
We are running on Windows 2003 Server.

Here is the query I am using to monitor the orphaned processed

12:59:28 SQL> Select USERNAME,PROGRAM,ADDR,PID,SPID,SERIAL#
13:02:27 2 From v$process
13:02:27 3 Where addr NOT IN (SELECT paddr FROM v$session);

USERNAME PROGRAM ADDR PID SPID SERIAL#
---------- -------------------- -------- ---------- ------------ ----------
PSEUDO 6BFCCB18 1 0
SYSTEM ORACLE.EXE (SHAD) 6BFD41D8 21 3960 89
SYSTEM ORACLE.EXE (SHAD) 6BFD5998 25 4284 96
SYSTEM ORACLE.EXE (SHAD) 6BFDA6C8 38 5604 77
SYSTEM ORACLE.EXE (SHAD) 6BFDBE88 42 3964 50
SYSTEM ORACLE.EXE (SHAD) 6BFDC478 43 5248 196
SYSTEM ORACLE.EXE (SHAD) 6BFDE818 49 4084 125
SYSTEM ORACLE.EXE (SHAD) 6BFDFFD8 53 1368 120
SYSTEM ORACLE.EXE (SHAD) 6BFE1D88 58 5584 116
SYSTEM ORACLE.EXE (SHAD) 6BFE2F58 61 4024 157
SYSTEM ORACLE.EXE (SHAD) 6BFE4128 64 4552 119
SYSTEM ORACLE.EXE (SHAD) 6BFE4718 65 3208 146
SYSTEM ORACLE.EXE (SHAD) 6BFE58E8 68 4232 15
SYSTEM ORACLE.EXE (SHAD) 6BFE5ED8 69 5344 193
SYSTEM ORACLE.EXE (SHAD) 6BFE6AB8 71 2740 19
SYSTEM ORACLE.EXE (SHAD) 6BFE7C88 74 2228 58
SYSTEM ORACLE.EXE (SHAD) 6BFE9448 78 5036 147
SYSTEM ORACLE.EXE (SHAD) 6BFE9A38 79 5620 154
SYSTEM ORACLE.EXE (SHAD) 6BFEA618 81 5752 20

19 rows selected..

I am contemplating going back to 10.2.0.1 to see if that will resolve the problem.
Has anyone seen anything similar to this or have any suggestion as to its cause/resolution?