DDPM breaks Windows taskbar

I use the auto-hide function of the Windows taskbar. With the old Dell Display Manager it worked fine. 

Since updating to the DDPM the auto-hide function is broken. When DDPM is installed and a window is in fullscreen, the taskbar can't be made visible by simply dragging the cursor to the bottom of the screen. Also you're able to drag a windows over the taskbar.

Until that's fixed, I'll keep DDPM uninstalled.