Same idea here!! Finding out how to fix it was piece of cake as I imagined that this would be so frequent that there would be a function. It took me something like 2 seconds to find it… and something like half an hour to figure out how the @#$%! Screencast function worked, well, 10 minutes to search for it in Stackexchange and the rest fighting against the darn thing to bend it to my will: every time you start again you have to set all the parameters anew and if you forget it you will get a whole bunch of PNG files clogging up your drive.
BTW, for clarity’s sake: Once you figure out how to select all faces (I select one and then use CTRL Keypad + several times) just go to Mesh > Normals > Recalculate exterior… or just CTRL N
So, here it is, a variation on the same theme 