Oracle Forms

I've installed the Oracle 9I database in the Windoes NT server with SID = ORA9i. Using the SQL*plus coming with oracle 9I database, I can connect to the database. I've also installed the Developer with Forms 6I and Reports 6I in the same computer. I tried to establish a connection to the Oracle 9I from Developer through "Oracle Net8 Easy Config". After giving the settings, when I do a connection test, it is giving the following error.

if i'm making a connection thru the 'Oracle Net8 easy config', it is giving the following error at time of connection test.

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The test did not succeed.
ORA-03106: fatal two-task communication protocol error

There may be an error in the fields entered
or the server may not be ready for a connection.
You can check the server and retry, or continue.
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this is the message i'm getting. but i couldn't find any error in the fields i entered.

if i'm editing the 'tnsnames.ora' file and make the connection, and when i open the Form builder and try to connect to the database, it is giving a memory error.

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the instruction at "0x67614f04" referenced memory at "0x000000160". The memory could not br "written".
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is there any additional settings we need for Oracle 9i on windows platform?

the following is the entry in the 'tnsnames.ora' file

TEST9I.WORLD =
(DESCRIPTION =
(ADDRESS_LIST = ((PROTOCOL = TCP)(Host = ntserver)(Port = 1521))
(CONNECT_DATA = (SID = ORA9i))
)