Five-Column Springboard is NOT IOS4 compatible.
I have IOS4 installed and I now have permanent safemode as It refuses to remove and it crashes springboard.
How do you remove it manually? Cydia keeps crashing when I try to remove it.
I was going to say try cydelete, but it's not on the springboard itself. You'll probably have to ssh into it and get it out manually. But that's just my educated guess. I'm sure someone with more experience may have a better solution.