I just got a memory card for my 404 (a sandisk extreme 3 if that matters) and intialized it like the manual said to and it appeared to work fine, but when I tried recording my samples they would play back with terrible clicks and strange panning, also sometimes the sample would not sound like the sample i recorded at all, it sounded almost like a circuit bent keyboard. But the samples that are on the internal memory appear to work fine so I'm not sure what to do? Is there anything I'm not doing or is the memory card the problem?
I went and got a ultra 2 sandisk memory card, put it in and it appears to work fine. So, conclusion that can be drawn: In my case at least, extreme 3 sandisk memory cards do not work with 404's