> Nevertheless, you can work around it pretty easy by sorting by seconds:
>
> mysql> SELECT risoluzione, inizio, timediff(risoluzione,inizio) AS delta
> -> FROM statistiche
> -> WHERE risoluzione IS NOT NULL
> -> ORDER BY TIME_TO_SEC(delta) ASC;

To make your query work, i had to change
> -> ORDER BY TIME_TO_SEC(delta) ASC;
in
ORDER BY TIME_TO_SEC(timediff(risoluzione,inizio)) ASC;
because mysql, told me that cannot find "delta" field...
boh?
anyway, do you know if delta could be too large to stay in SECOND TYPE
and so reset itself to 0?

I hope I explained clearly....
tnx again