Although I'm not sure if problems can be fixed (as they seem very specific), I'd like to report two problems I found with 3551 Alpha that I didn't have with 3550 : - Using the Dynamics Processor plugin, my card becomes absolutely silent once I load a .kx config in which they are used. Using the VU-meter plugin, I can see that the sounds "disappears" once it reaches this plugin. To get the sound back, I must fiddle with the Dynamics Processor potentiometers : modifying the plugin's configuration by playing with the pots gets the sound back. - Using some older .kx config files, my sound gets stuck in a kind of infinite loop : it sounds like what's being played is being recorded, and what's being recorded is played slightly louder. That sound is then recorded, then played even louder and so on until after a few seconds there's only a huge loud distorted mess of echo. It wouldn't do that on 3550. And it doesn't do that when I make a whole new DSP config. But I couldn't figure out what's the difference between the old and the new DSP config that could explain the problem appearing or not. - I think there's a bug with WaveHQ and some video games. I remember playing Prototype with WaveHQ set as default, and the sounds were all sped-up and with higher pitch. - And of course, all the problems everybody has already heard of : sliders not working, UAC problem, last DSP setting not loaded at startup (apparently a matter of wrong kxmixer.exe called by Windows at startup), SoundFonts not supported, SPDIF/AC3 actually being Wav0/1, etc. Using an Audigy 2 ZS with Win7/x64. Hope some of those can be fixed! A bug-free version of kX would be pretty much heaven!