Uhmm, ok, i'll try another time. following your method. Surely, the uniaud version that works is the one from Paul Smedley, the test version on netlabs ftp server, since the ACPI version 2.20, so, usually, i install the AC97 from regular mmos2 setup and on reboot i change it.
About the Desktop rebuild:
http://wiki.netlabs.org/index.php/Rebuild_your_eCS_desktopBut i never tried it before.