Oracle 10g; Windows 2003 server

This server/db is about 2 weeks old. It was working fine but now the connection to db are getting real slow or they are failing most of the times. The error it shows are:
TNS-12571: TNSacket writer failure
TNS-12560: TNSrotocol adapter error
TNS-00530: Protocol adapter error
32-bit Windows Error: 54: Unknown error
TNS-12500: TNS:listener failed to start a dedicated server process

See this from actual listener.log:
-------------------------------
29-AUG-2006 10:12:17 * 12502
TNS-12502: TNS:listener received no CONNECT_DATA from client
29-AUG-2006 10:12:17 * 12502
TNS-12502: TNS:listener received no CONNECT_DATA from client
29-AUG-2006 10:12:17 * (CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=MYDB)(CID=(PROGRAM=D:\oracle\product\10g\db_1\bin\nmup m.exe)(HOST=MYDB)(USER=SYSTEM))) * (ADDRESS=(PROTOCOL=tcp)(HOST=IPADDRESS)(PORT=2380)) * establish * MYDB * 12571
TNS-12571: TNSacket writer failure
TNS-12560: TNSrotocol adapter error
TNS-00530: Protocol adapter error
32-bit Windows Error: 54: Unknown error
TNS-12500: TNS:listener failed to start a dedicated server process
TNS-12560: TNSrotocol adapter error
29-AUG-2006 10:13:39 * (CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=MYDB)(CID=(PROGRAM=D:\oracle\product\10g\db_1\bin\nmup m.exe)(HOST=MYDB)(USER=SYSTEM))) * (ADDRESS=(PROTOCOL=tcp)(HOST=IPADDRESS)(PORT=2383)) * establish * MYDB * 0
29-AUG-2006 10:13:39 * (CONNECT_DATA=(SID=MYDB)(CID=(PROGRAM=D:\oracle\product\10g\db_1\perl\5.6.1\bin\MSWin32-x86\perl.exe)(HOST=MYDB)(USER=SYSTEM))) * (ADDRESS=(PROTOCOL=tcp)(HOST=IPADDRESS)(PORT=2385)) * establish * MYDB * 0
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After listener restart, it worked fine for few minutes and then started showing errors like before. There is no error in sqlnet.log file.

Please suggest whats going wrong here and its fix. I have 5 other servers like that and they are all working fine.
-D