When installing multiple products (series of discs), we've found that the icon behaviour of the installed files has been very confusing. The icons have been applied through a .dll file and depending on the installation order of the msi files, the respective application icons do not necessarily apply correctly:
Disc 4 - Icon 4
Disc 5 - Icon 5
Disc 6 - Icon 5
Has anyone else come across this behaviour - it seems to affect anything below XP.