VS2003 7.1.6030 (SP1) + Carbide.vs 2.0.1 + SDK 3rd MR
1) Open pkg file in VS editor
2) Add some external file with ,FR,RI
3) Make sure "Update pkg file" is checked in project properties
Last letter of line you've added is replaced with double quote (huh?!) and packaging fails.
Solution is to write each install option in double quotes: ,"FR","RI"