Session needs much too long to open an old session

Does someone know why my cubase 6.0.7 needs up to 30 min to open an 6.05 session?
it seems to be that cubase cant find the samples for the instruments, because these are loading very slow…
but is there a way to speed it up? when i open sessions that are created in 6.0.7 its as fast as it should be.

thanks for your help