same here.... i have a PCIe (1.3 if i'm not wrong) and a PCI (1.5) and the multiface connected to the PCI is number one.
I had to reorganize live's preferences and the patchaby (this was the less funny bit, since I have 4 patchbays and things are very very cluttered) but i was even less willing to open up the computer and try some card swaps than reconnect some cables in the patchbay.
I tried to have two multifaces II working together with just one PCIe card and I couldn't get them to work, i got a PCI card for cheap and now I'm happy... 20 outs and 16 ins are nice, since I have a large desk with a very nice sound, so I can finally mix on the desk and not just route busses on 8 channels.

We already had something similar in another thread. This behavior becomes a problem for Pro Tools Native users, because of the 32 channels limit.

I had a look at the Registry and found that Windows seems to stick a *random* but *permanent* number to every audio input/output ever present in the system. The problem is that in the Registry these audio ports are then sorted alphabetically by *key* name aka by ascending *random* numbers. This leads to all ports being shuffled around each other without any particular order.

It's the job of the audio software to sort the ports in a useful manner and there even is another location in the Registry that does the sorting alphabetically by *port* name. Media Player Classic is one software that makes use of that specific Registry sorting and thus offers a far more usable list.

One could try to see what happens when the numbering of the Registry keys is changed manually.

Ok, guys. I went through all possible variations and no change. Changes pci slots etc....the numbering stayed the same all the time. Although i had two rev.1.9 cards in and they were numbered 1 & 2, always when installing the 1.4 card it became nr.1.

So, in the end i just decided to use MFII with 1.4.

One funny thing is that MFI's have some weird noise in the unbalanced headphone/line out channels. Its linked to graphical activity. I was thinking it has something to do with having too little power....and yes, It disappears completely with ext. PSU!!! So, i decided to use ext PSU on all MF's and it makes the noise floor slightly better on all channels which is no wonder as there is 1A power and the audio in the same cable. Very recommended.

I also use word clock to sync them although i'm not completely sury if it is necessary as there reads that cards nr. 2 & 3 get their time code from card 1.?!

With 3x MF with word clock and ext. PSU's this setup is amazinly good sounding 30 analog out/ 24 analog in setup.

Actually I assume that the numbering problem is because once Windows has decided the order of the cards it stays the same no matter what. So to fix this i'm guessing that registry might be the target....

I dont know if it's general or not but i'm definitely not the only one with this problem...and the solution of ext PSU works perfectly.

I'd say it's because you have 1A power and audio too close... or just too weak current/bad grounding. Only comes to suface with unbalanced line out/headphone.