Why is Twitter for iPhone constantly logging me out?

Hi!

I have an iPhone 3GS (on iOS 6.1.3) and the Twitter (latest version) app constantly logs me out. Beforehand, the app will experience a freeze then the next thing I know is that I'm in the login screen of the app. This is ******* me off since logging back in again discards my settings and drafts data. Any explanation/help about this?

Thank you!