'Mismatch in Datapacket' - Error

I am getting 'Mismatch in Datapacket' error when I try to apply chages to
TClientDataset. It occurs only when I tried to add new master record and
change any field(primary key fields are hidden) of master record and then
add detail records to it later. It allows me to add master record follwed by
detail records to apply without editing master record fields.

Could any one help me out?

Cheers,
Chandra
chand...@pec.co.nz