Windows 7 Explorer - Increase Delay Time When Dragging&dropping?

I use Windows Explorer heavily. I am constantly moving files and batches of files from one folder to another. I have one very annoying problem with this but I bet there is a way to fix it.Here's what I do - I highlight several files in the right pane, I hold down the right-mouse-button over the selected files, I drag them over to a folder in the left pane, and then the annoyance happens. If I don't drop those files immediately into that folder, the entire list of sub-folders pops open as if I hit the little plus to the left of the folder. What makes this a major annoyance is that the folder I wanted to move into has now changed its position in the left pane because the sub-folders popped open.

Now, sometimes I desperately need the sub-folder list to open because I forgot to find the folder I needed before moving the files. It is a nice feature. However, if only I could increase the delay-time. I'd like to give myself triple the time to drop the files into the folder before the sub-folder list opens. There has to be a registry tweak for this.