Call transaction using FB02 Tcode

Hi All,

In BDC program i have used call transaction method for tcode 'FB02'.

When i am running - in All screens mode it is working fine.

- in No screens mode then it is not updating and also not giving any error messages.

updating mode : I have checked with the both S and A.

some time it is giving error number:344 , 304 like.

But i am not able to see the error description.

Some one might come accross this problem.

Help me in this case....

Regards,

Anil