If your looking for a multi-track recording mixer, and you are stuck on CakeWalk (I have heard of no similiar problems with any other software), I'd maybe recommend investing in the Mackie firewire line found
here. Make sure the package you get comes with the firewire add in, because it's not built in and they can come without it. This is what I would invest in instead of the Alesis, that is, if it would be impossible to get my hands on a Digidesign/protools solution.
The Alesis "is" working fine for me right now. You have to run CakeWalk with only one of your cores in your dualcore/multiple cpu system (even though the program itself supports multiple CPUs), and the weird playback problems disappear. Apparently this bug is on Alesis's side, and hasn't been fixed going on a full year or more. The Alesis's come with Cubase so it seems to me they just don't care about anything else, but still promote that it's compatible. Which it is...
Now, I've personally had problems with WDM vs. ASIO in cakewalk, as well. I hear this is fixed by using older drivers, but the only real problem with using ASIO is that it forces you to use the mixer as the output as well, while with WDM you can use your computer's sound card instead.
The MultiMix works, but I've found I waste a lot of time troubleshooting, even now after I have it figured out. But for it's price, it's really the only thing there is. Still, saving up for Digidesign or the Mackie is probably the better option.
hope that helps with your decision ;)
Tyler