"in my experience, google gives different importance to a web site when it has one link from dmoz. there is a special part related with dmoz on google algo." I disagree; I've seen no evidence of that at all. Dmoz links carry a lot of weight because many other directories use DMoz listings (Excite for example) so you get a bundle of backlinks not just 1 and many of these too will have PR of 2 or 3, but I doubt Google have specifically given certain sites more weight than others, the whole point in Google having an algorithm is it's supposed to work all this out itself.
Most DMOZ clones are discounted through duplicate filters within Google... The noodp tag was given by google because they understand that DMOZ has a few flaws in their description processes, so pointing that out is a point against DMOZ if anything... DMOZ does have a DMOZ clone itself, but again, that is not all that much of an indication of google liking the directory, as they have been known to go well over a year without bothering to update it.