Yamaha Steinberg FireWire driver v1.7.2 for Mac OS X

Dear All,

Running the fire wire driver on my MacBook pro is a disaster. It will not load automatically. Sometimes it does, 9 out of 10 it does not. Running on my W7 ultimate system is not a problem, but I need it on my MacBook pro. Why is it not loading, why is not recognized by the OS 10.5.8 <Mountain Lion. It is very frustrating. It needs to work with the MR816csx, but no driver no response by cubase7.

System
MacBook pro 15 inch
Internal memory 8 gb
2.7 gHz processor i7
OS mountain lion 10.5.8

Tyros4
Motif xf6 (including fire wire card)
MR816csx

Windows7 ultimate, 64 bit, RAM 16 gb.

Willem