Your data should be safe since it's saved in a location separate from the application itself. With that in mind, you might try simply deleting the application and installing a fresh copy. For that, drag the CheckBook.app file into the Trash from the Applications folder and then, if you purchased from our online store, download from our site here:
http://www.splasm.com/checkbook/index.htmlOr, with a copy purchased from the Mac App Store, log into the store, and re-install from the Purchases section.
Now, if that doesn't do the trick, we'll need to gather some more information about what caused the crash. For that, we'll want to see a copy of the crash logs for CheckBook as well as a System Information/Profiler report for your Mac. So, would you be willing to send that stuff over to us via email?
If so, to access that information, you'll want to replicate the issue in CheckBook and then just after locate the crash logs for it by launching /Utilities/Console.app (in your Applications folder) and looking in the "DIAGNOSTIC AND USAGE INFORMATION" section along the left side of the window. Search inside the "User Diagnostic Reports" subsection and you should find at least one CheckBook item. Drag the most recent of these to your email message to us at
support@splasm.com and it should act like an attached file.
Next, choose 'About This Mac…' from the Apple menu at the top of the screen, click the 'More Info…' button, and then hit 'System Report…'. That'll bring up the System Profiler/Information report and so to save it, choose 'Save…' from the File menu. Finally, attach this file to the same email to us.