I have an iPad 1 running iOS 5.1.1. - iBook Store, App Store fail

I am experiencing an issue with both iBooks and the App Store where I get thrown out seemingly randomly when browsing for books and apps. I perform a search (sometimes 2 or 3 successfully), get a list of results, select an item to view and then the app closes and leaves me at the home screen. When I reenter the app I find my search field contains the text from the last time I exited the app normally.

I have not yet reset the device and wanted to avoid the time and trouble required to do so.