Please see my reply in
this thread for more information about the store restocking issue.
The crashing is something that is caused when application memory gets critically low and the operating system shuts down the running application. Resetting the iPhone frees up memory. Application memory is different from the 32 GB of flash memory that you use to store apps, music, etc. on your iPhone. iPhone OS doesn't provide a way for you to see how much application memory is available on your device, although you can purchase applications that will display that information.