Mini freezes (spinning pinwheel) after FusionDrive upgrade

Hey guys!

I just recently installed a Kingston SSDNow V200 128GB with the iFixit dual hard drive kit, set up a core storag logical volume in terminal. Since then the mac freezes after about 5-10min of usage. The spinning rainbow wheel pops up and I have to hard reset the mac. Does this have something to do with the data chunks which have to be moved? I already tried splitting up the drive, format and reinstall. No luck...