I had this problem. I didn't use the 'hide taskbar' because it seems a touch slow to 'hide' the taskbar. I simply moved my taskbar to the side and made it as small as possible. I had this same problem with MediaCar and moved the taskbar to the top and didn't have the problem anymore.
[|||||!||||'] 95% complete
It's in... it's finally installed!!!! But never finished!
"It works! It works! I've finally invented something that works!" -- Doctor Emmit Brown