[LAU] ua-25 very noisy in advanced mode

Hello list! I've searched about this issue without success. I hope someone of you smart guys brings me any idea. The problem is: Edirol UA-25 sounds very noisy when in advanced mode. (I need it in advanced mode because in normal mode you can't use the midi ports and the sound quality is limited to 44.1khz 16bit) And when I start jack, I must configure it with 3 periods and 1024 frames minimum to eliminate noises. This is a new Debian Sid installation Ok, now the strange thing is that before reinstalling my system I was able to use the same soundcard in Debian sid, using the the same machine, same hardware, same kernel I'm using now (I recompiled with the same .config) with a very low latency (64 frames 2 period, 48000 hz around 2-4 msec). The only diferent is that I installed it from 0 two days ago. And, I've not lost my previous system. I have it in another partition, so I can take a look to any old-system's configuration file. But I've not found any clues!! Oh! I forgot to mention that some months ago, when I first installing debian I remember having the same problem so I used it in normal mode. But one day I tested advanced mode and it just worked! magically! that is not of much help because I don't know what I did. So I think I've discarded some bad kernel configuration by running my previous kernel. I've even tried recompiling the alsa libraries, and I'm using jack cvs head. do you have any clues? I'm really loosing my mind with this ;) hahaha greetings! joseLuís