Using Instruments 'Allocation' with an iPad App-Collection of common programming errors

I’ve got an issue with my iPad app. After running for approx. 15 minutes, it crashes with “Program received signal: “0”. showing in the log file. From Google, I’ve discovered this is probably a memory useage problem. In the Console log on the iPad there’s also a couple of memory warnings before the crash which seem to confirm this.

I’ve run my app in Instruments (xcode ‘Run’ -> ‘Run with Performance Tool’ -> ‘Allocations’). This is where I start to get a bit confused. Instruments shows me ‘Live Bytes’ and ‘Overall Bytes’. As I understand it, ‘Live Bytes’ is the actual memory ‘footprint’ of the app, and ‘Overall Bytes’ is the total count of all the memory that’s been allocated and subsequently released. In my app, ‘Live Bytes’ sits at approx. 1.5 MB, while ‘Overall Bytes’ gradually rises to 500 MB at which point the app crashes.

My question is how much memory is my app actually using? 500 MB certainly seems like a problem for an iPad, but 1.5 MB certainly doesn’t.

Thanks

Stuart