Status of my analysis :
I have no proof of this, however, comparing my 2 PC's (both 64 bit win 7), one has a successful SQL server installation (through Visual Basic),the one that builds the song list properly.
The other failed to install it. As a consequence, many things using SQL routines don't work (not even Windows Live, that cannot install !). Microsoft is aware, but was not able to find a solution/workaround so far (they advised me to re-install from scratch... ;o). I suspect that building the songlist file may use a SQL routine.
Cheers,
Yvan