Yeah, I have the MultiMix8 Firewire and am having much of the same problems that everyone else is getting. I emailed tech support and got a reply asking for my phone number and a good time to call.
I get a lot of stuttering when I try to monitor through Sonar 4, only when I playback or record over a previously recorded track. Plus it happens when I just play rewired into Reason. I have a US 122 also, but that never gave me the problems that the mixer does. I think that is Sonar though because I play through Reason by itself and have no stuttering at all.
I have a SB Audigy card that I use for playback because sometimes I can't get items to play through the mixer even though my sound settings have it correctly set to the Alesis. I also find that if I keep the computer on, the firewire connection will just turn itself off. Not only that but now when I play games and then quit them, all of a sudden (not every time) I lose all audio interfaces...my control panel sees no audio input. Weird. This has only happened since I installed the drivers for the Alesis. I also upgraded to the newest ones with no difference.
So far, everytime I've gone to record, I have had problems and set backs. Since I don't have much time on my hands, this piece of equipment is almost useless. Unless I get some kind of resolution within the week, I'm bringing it back. I have too basically.
Specs:
Dell
Windows XP Sp2
Intel 4 3.0 Gz
1.4 Gz Ram
24 plus Gigs on both IDE hard drives
SB Audigy
ATI Radeon 9800 Gfx card.
I do lots of multimedia/3d animation and video, so I need a pretty powerful system. I think I'm pretty OK in that respect.