Why Do Breakpoints Fail When Multiple Source Files Have the Same Name?
If two or more source files in the project have the same name, breakpoint problems are likely to occur. This often happens in cases where the user-named module has the same name as one of the components of a library (Debug version) they are linking with.
To work around this problem, try using the Context selection on the Advanced Breakpoint dialog box. In most cases, you can use the full paths to the source file and corresponding executable module.
For more information, see Setting Breakpoints at a Memory Location Within the Current Scope.