Problem connecting to a oracle database

[akki]

I am trying to connect to an oracle 10.2 database from my asp.net
application....but i am facing problems in doing so.
I am using OleDB connection objects and my connection string is like
this:
Provider=OraOLEDB.Oracle;Persist Security Info=False;User
ID=aaa;Password=xxx;Data
Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOC OL=TCP)(HOST=w.x.y.z)(PORT=5500)))(CONNECT_DATA=(S ERVER=DEDICATED)(SERVICE_NAME=abc)));Connection
Timeout=60

I can connect directly to the database(abc) from the browser through
http://w.x.y.z:5500/em
But when I run the asp.net application i get the following error
ORA-12569: TNS:packet checksum failure

Can somebody please help me out here.....

Thanks
Akshay