pokemon explorers of the sky freeze

i was just playing explorers of the sky and got to treeshroud forest and when i want to go in the cave it freezes, sometimes i get in the cave but then a few floors later it freezes aswell.. could someone be so kind and help me? thx in advance

Give more info
http://forum.romulation.net/index.php?topic=1736.0Also see this
http://forum.romulation.net/index.php?topic=1462.0

my game freezes when i try to go in treeshroud forrest
pokemon explorers of the sky
im using it on r4

works fine for me in using a r4sdhc