Native applications can't be debugged after upgrade to 1R7

I just upgraded to R7 from R5, and my native test applications can’t be debugged anymore. It still compiles and run, but there is no way to set a valid breakpoint in Visual Studio. I have checked that the “strip” option is off and that my code is compiled with debug info. The project itself is the same as it was in R5. What am I missing?

Thanks for any tips!
Mathieu Jean