hi everyone

I'll start with my system:
O/S Win7 64bit, Intel i780x
12gb ram running @1600mhz Corsair DDR3
Rampage 3 Extreme(which has an Firewire TI chip)
RME Fireface 400, Driver 2.9992 , Firmware 1.70 connected to a Yamaha O2R via Optical using the RME internal Clock and the O2R syncing to the RME.
3 Monitors running on 2 GTX480 in SLI
PCI firewire Card using TI chip
DAW Cubase 6

I am having this issue, when I start up my computer and the fire face is connected it crashes my computer 9 out of ten time, I have to disconnected or switched off my RME400 prior to boot up, then turn it on once my computer is fully booted. I have connected the Fireface 400 via my PCI card and straight to the motherboard and the problem still continued. I also connected it with the RME’s own power supply instead of using the firewire power and vice a versa and the problem still there.
I installed the latest drivers to no avail, only to encounter another problem, whereby the driver was telling me to install fireware 2.77 on a RME400 which my card would not except. 
I am also experiencing instability when using Cubase which sounds like the RME freezes and just repeats the last sound it plays prior to crashing. I have found that this is more profound when changing Virtual Instruments but not all the time, sometimes there appears to be no apparent reason for the freeze and I have to turn the RME off and restart Cubase which I am finding very disruptive to my creativity and work. I am also experiencing slight pops and clicks every now and again, I have ran DPCLAT  and there appears to be now background programmes making my computer go over 500us and the program reports that my computer should be able to handle audio and video without drop outs.  I could except that there may be some plugs ins  causing the instability in Cubase, but cannot understand why the RME is making my computer crash on start up. I have undertaken various bois configurations to try and sort the issues out, but it always boils down to the RME400, because when it is not connected I have no issues on start up. When the RME is running it does a reasonable good job,
i just wish that the drivers were a bit more stable.

I would appreciate your assistants with this problem and look forward to your replay.
All the best John.