I tried the installation with these parameters inside a InnoSetup script:
/SP- /VERYSILENT /NOICONS /COMPONENTS="ServerComponent,
SuperServerComponent, DevAdminComponent" /FORCE

The main difference then previous release are:
1) The applet is not installed
2) Guardian is not installed
3) When you restart the pc the server is not active

I don't know if it is a bug...

I'm going to study how use the Firebird-2.0.0.12748-0_win32.zip

Fabio.