There's a bug that causes the phone to take a minute or so to respring and is supposed to be fixed today. Don't freak out or try to boot into safemode (like I did and ended up restoring until this thread popped up on reddit). It will take this long no matter what with the tweak installed.
Here's the thread and comment from the dev on the issue - http://www.reddit.com/r/jailbreak/c...2_causing_black_screen_after_respring/cnjt8mm
Here's the thread and comment from the dev on the issue - http://www.reddit.com/r/jailbreak/c...2_causing_black_screen_after_respring/cnjt8mm