Reflective modalities and theory change

In 'Belief Revision and the Ramsey Test' (G~irdenfors, 1986) Peter G~irdenfors has shown that a prima facie plausible acceptance condition for subjunctive, conditionals is incompatible with a certain apparently equally plausible requirement on how a rational agent should change his beliefs in the light of new information. The above mentioned acceptance condition for conditionals is the so-called Ramsey Test.