C++ mode, switch from Code to Debug (e.g start debugger), then switch back (end the debugger). Now when you are back in Code mode, more than one toolview is visible at once (Debug, Build for me). Double click on Build, click on Debug working set: again two are visible. And so on. You might even get 3, 4 views visible at once...
isn't this a duplicate of bug 287093 and hence fixed since yesterday?
*** This bug has been marked as a duplicate of bug 287093 ***