Just to clarify further, when I restart or wake my PC, DC is running in the background (visible in processes and icon is in tray), but it's not doing the corralling. I have to restart the process, and then it pushes my other windows down, as it should be. The reason it's an issue is because my Samurize banner is visible at the top of my screen (which DC is supposed to corral), so the tops of my windows are obscured by Samurize, which makes it difficult to move them, close them, minimise them etc.
It's not a big deal to restart the DC process, but I was just wondering why this is happening (whether it's something with my system or something with DC). I should add that my PC has been prone to crashing when it's woken from sleep, so it's also possible that I might be having a deeper system problem at my end.