SSIS package hangs/fails while importing data from Oracle9i

Hi,

I am trying to import data from Oracle9i to SQL Server 2008 using SSIS. The issue is that it works fine sometimes but sometimes it hangs and some time it failes with below message

[Oracle Source [1]] Error: OCI error encouneterd. ORA-03113: end-of-file on communication channel
Process ID: 5378
Session ID: 773 Serial number: 12319

[SSIS.Pipeline] Error: SSIS Error Code DTS_E_PRIMEOUTPUTFAILED.  The PrimeOutput method on component "Oracle Source" (1) returned error code 0x80004005.  The component returned a failure code when the pipeline engine called PrimeOutput(). The meaning of the failure code is defined by the component, but the error is fatal and the pipeline stopped executing.  There may be error messages posted before this with more information about the failure.

Please suggest me how to solve this issue.

Thanks in advance.