         if !aObj.uid {
             // only NEW object have a nil uid
             
-            var pos  = self.register()
+            var pos  = self.registerBlock()
             result = self.calculateID(pos)
             aObj.uid = result
             

            // store SampleData as ID:0 in the file
            // ID:0 is a reserved ID and should not be availabled for public access
            var header = ObjectStoreHeader(used: false)
            self.writeHeader(&header)
            
            let sampleData = O()
            self.writeData(sampleData.data, atPos: CUnsignedLongLong(self.fileOffset))
            
        } else {
            let pos = calculatePos(1)

        
        if aObj.uid {
            self.cache.removeObjectForKey(aObj.uid!)
            self.deleteBlock(aObj.uid!)
            aObj.uid = nil;
        }
    }
