Day Bank doesn't work after jailbreaking. Doesn't this say something?

The app store app called Day Bank, simply crashes upon entry after jailbreaking. I deleted and reinstalled several several times, rebooted the iphone, nothing doing.

This is a new iphone 3g, and when I jailbroke it, I set it up as a new phone, so I know I didn't have old settings on it. I emailed support and they asked if I jailbroke it and said if so to do a restore.

Sure enough, I restored it back and the app works. Granted, Day Bank isn't a hugely popular app, but I like it and paid for it. But the bigger question is if jailbreaking affected this app, what other apps could it potentially be causing problems with?

And also, why did jailbreaking the iphone affect this particular app?

nope. I tried deleting and reinstalling both through iTunes and the iPhone itself. It was authorized. The program started just fine. It just crashed afterwards. I firmly believe it was the jailbreak unless anyone who has Day Bank and a jailbroken iPhone can prove otherwise.