I tried it on another computer, and it worked, so I am kinda relieved. So it is something with my Mac Book Pro. The thing is, my MBP is recognizing other devices, so it is something between the FF400 and the MBP itself. Any clues?

Well, I just posted this on the apple support forum and that may make my problem clearer:

I am having a very big problem with my 13" Macbook Pro since yesterday. I took it to work and hooked it to a RME Fireface 800 audio interface we have in there, and for some odd reason it didn't recognize the interface. After a few tries, it suddenly came alive. I did the recording session as usual, turned the notebook off and brought everything home. Today, I hooked it to my own RME Fireface 400, and one of the firewire ports on it wasn't working - I plugged on the other and started audio playback. After a few minutes, the audio stopped and the host connection problem led the Fireface has turned on. AFter this, I couldn't get the fireface to be recognize on its own - more on this later.

I went to system profiler and got a 'WARNING: Unable to list firewire devices' message. I already googled it and it seems I am not the only own having this problem. I already clean PRAM, SMC, ran disk utility to repair disk and disk permissions and nothing has worked. HOWEVER, one external HD (firewire) i have is working just fine on this same firewire interface. I also tried daisy chaining the Fireface to the Hard disk, the later being connected itself to the Macbook, and using this method the interface works. I also tried the interface on another computer and it works just fine - so the problem lies on my Macbook Pro.

Now, I went to the Console application to see if there was any error messages, and in fact there are plenty. I got a bunch of 'FireWire (OHCI) Lucent ID 5901 built-in: Bad selfIDs, issuing bus reset (retry 2)' and then 'Missing self ID for node 0!'. Also got some 'Firewire (OHCI) Lucent ID 5901 built-in: 4403 resets in last 3 minutes'. Also 'SPFWR ERROR: Firewire bus may be unstable. Other Firewire devices may be present.'. Right now, If i plug the interface and look for something on the console, I get nothing. I only get something when I look on the System Profiler.

So, obviously, there's a problem between my interface and the MBP. Anyone has ANY clue on what to do? BTW, the interface don't work when booting to bootcamp using W7 (it is also not recognized).

So, basically, i tried another cable on this MBP (and it didnt work), I tried it on another computer and it DID work (although I may say that fireface settings crashed both times I tried on this other computer, but this may be the computer's fault - it was kinda buggy), and it DID work when daisy-chained to a external hard disk. The hard disk also works OK when alone on the firewire bus. So it is obviously a problem between the two. I just need to figure out which one and the problem itself.

Btw, no difference whatsoever by using the external supply or not.

Sound like a broken Firewire port to me, question is whether it's the one on your Macbook or the ones on the Fireface.

You are using a 2010 Macbook Pro (revision 8 Lucent FW chipset)?

And what about the power-supply question? Does it make any difference whether the power-supply of the FF is used or not?

Does the HD work when you put it after the FF in the chain?

It's refreshing to find a representative of a manufacturer who leaps to the conclusion that THEIR unit is broken, rather than trying to blame everything around it!  :-)

Where did you purchase the unit?

Regards
Daniel Fuchs
RME

Daniel, I just contacted the dealer and they forwarded me to their own tech support (the dealer ins affiliated to Um Instrumentos). They gave me a repair time of around 35 days IF they have the parts on stock and 45 to 60 days IF they have to order the parts directly from RME. This includes 7 to 10 days for testing. Is there a more reasonable solution for this? Two months without working is just..too much.

I'm not sure what you expect us to do from here... We have no direct influence. So unless you wish to ship the FF to German (which will not likely be faster), you will have to deal with Um Instrumentos and see what they can do for you locally. Maybe they have some kind of temporary alternative for you.

Regards
Daniel Fuchs
RME

Well,

it isn't likely to be a lot faster, and customs will have their say on both trips, but of course the device could be shipped to this address:

Audio AG
Am Pfanderling 60
D-85778 Haimhausen
Germany

Phone: +49 (0) 8133 918170
Fax: +49 (0) 8133 9166
E-Mail: info@audioag.com
www.audioag.com

Regards
Daniel Fuchs
RME

dido1, it seems like something is causing trouble on your Mac Pro Firewire bus. Try it with all other FW devices disconnected, especially the Cinema Display FW connection.

Yeah.  People expect Macs to be faultless.  They aren't, of course.