not getting any messages into message tab call transaction

Hi ,

i written one bdc program with CAll Transcation method,

and i ams displaying the message log by using message Tab after call transaction,

It is working fine for most of the times,the MSSTAB getting messages, but for some it is not getting any messages,when we checked the interntable of messtab, it has zero Records,because of this we are not able to display the message log and we dont knw what records are processed...

Can anybody help me on this to resolve it. why it is not getting any messages into MESSTAB..

Sri