Oracle Database Discussions

Hi All,
I am trying to process data in n-Number of tables through a package. The package is called through a shell script to create start data processing. All calls to the package are in a sql script which is basically exec calls-

exec package.process ('T1','some param');
exec package.process ('T1','some param');
....
....
exec package.process ('T..n','some param');

I have a shell script which I use to execute commands from the sql script. There is a reason behind using shell script. For some strange reason, I keep on getting -

ERROR: logon denied - check for valid user with valid privileges
SP2-0640: Not connected
SP2-0641: "EXECUTE" requires connection to server
SP2-0640: Not connected

for some EXEC calls. Problem is, errors are generated at random. So in one run, I get error for T10,T11 and then in next run I might get for some other tables.

However, when I am running the sql script from the sql prompt, all calls to the package are executed without any problem.

This makes me think, it is something to do with the way database connection being initiated through UNIX.

Has anyone faced similar issue? Your help/gudence is much appreciated.

DB: Oracle 10.2.0.5
OS: SUN Solaris 10

Thanks in advance.