I've installed Leviton No 5634 - 2 switch light control to replace one that broke. Have one common power line with 2 lines for lights plus ground. Installed per directions, however, doesn't work properly. I did NOT break off fin! PROBLEM: One switch "A" operates one light and the one switch "B" operates other light. However, in order for B to work A must be on. If you turn off A switch it turns off both lines. Any help would be appreciated.