I have similar issue. Debugger hangs when I try to step or use breakpoints and no way to stop it except closing whole C::B or killing gdb process.
I wasted some time and found that problem appears when I using Linux line endings in the .cpp file (C::B is running under Windows).
If I convert .cpp to the Windows line endings, problem disappears.
Now I have a question, is I really have to use Windows line endings to debug under Windows, or there is some options could help me?
If I have to use Windows line endings, then how about Linux? Will debugger / gdb work fine with Windows line endings under the Linux?
PS: Don`t sure if it usefull, but my system is: Win8 x64, C::B 12.11 release, GNU gdb (GDB) 7.5 (installed with C::B). Also tried nightly C::B build.