Lb1fixmod

This is a modification to your lb1 fix pull request.  I took a shot at cleaning up the issues I mentioned.  If you want to test this out, then pull it into your branch if appropriate, we can then move your branch into release/2.9.  

To test it load up the library browser
1) Hide a problem with an M
2) Expand a problem with an M and remove the top problem.
3) Expand a problem and remove all the problems one by one
4) Check that this new expansion/remove behavior doesn't impact adding problems or other functionality.