Multitasking and shortcut keys

[Merlin]

I noticed that when doing a background copy or foldersync the program doesn't react to shortcut keys anymore until the copy/sync process has finished.
I can help myself by clicking the menu-options and buttons but it would of course be faster to use the shortcut keys.
Maybe it would be good to look into the multitasking part of the program and give the copy/sync process less priorities if that is possible...