insert into mseg extremely slow

Hi all, We are running ECC 6.0 EHP 6. We are currently experiencing an extreme performance degradation when using transaction code BD87. Monitoring SM51 the insert into MSEG can take up to 87sec (or even longer) if an IDOC is involved. However, if we do the same Transaction using Transaction MIGO we do not have any performance issue at all. Any help is greatly appreciated since this is a production environment and pallets are starting to pile up. Martina