Thanks for your answer.
it is very strange indeed.
I installed the MC160039 on a second PC, with a different OS (XP) and another CD driver, but the problem is still there:
with this Pc too, the track n.1 is skipped when the ripping action starts.
I think it is not related with the kind of compression used, as it rips the track 2 at the very beginning of the action.
If I rip the same cd again, this time it starts from 1.
But with a new CD starts again from 2.
With MC15 this problem doesn't happen on both the PC's.
Here the secure rip log :
Secure Rip Log created at 15:59:01 luned́, febbraio 28, 2011 - Media Center 16.0.39
Symphonies Nos. 25-27, 29, 32 - Mozart, W.A. >>> Drive D: PLEXTOR DVDR PX-880SA Mode:ModeSecure Type:Auto Speed:Max
Track 2: Secure rip, no re-tries. [25.2 Andante]
Track 3: Secure rip, no re-tries. [25.3 Menuetto - Trio]
Track 4: Secure rip, 1% of sectors needed re-reading. [25.4 Allegro]
00:01:40 2 re-reads required to get good data
Track 5: Secure rip, 1% of sectors needed re-reading. [26 Molto Presto - Andante - Allegro]
00:06:18 2 re-reads required to get good data
Track 6: Secure rip, no re-tries. [27.1 Allegro]
Track 7: Secure rip, 4% of sectors needed re-reading. [27.2 Andantino Grazioso]
00:02:02 2 re-reads required to get good data
00:02:13 7 re-reads required to get good data
00:03:28 2 re-reads required to get good data
Track 8: Secure rip, 1% of sectors needed re-reading. [27.3 Presto]
00:03:03 2 re-reads required to get good data
Track 9: Secure rip, no re-tries. [29.1 Allegro Moderato]
Track 10: Secure rip, no re-tries. [29.2 Andante]
Track 11: Secure rip, no re-tries. [29.3 Menuetto - Trio]
Track 12: Secure rip, 1% of sectors needed re-reading. [29.4 Allegro Con Spirito]
00:01:40 2 re-reads required to get good data
Track 13: Secure rip, 1% of sectors needed re-reading. [32 Allegro Spiritoso - Andante - Primo Tempo]
00:00:14 4 re-reads required to get good data