There are many reasons that an App may crash. Follow these instructions to rectify the problem:
http://www.apple.com/support/ipad/assistant/application/
If your iPad has frozen or become unresponsive, follow these instructions:
http://www.apple.com/support/ipad/assistant/ipad/
We strongly advise against downloading an entire magazine via 3G. A magazine can be as large as 200-300MB so we recommend that you use Wi-Fi. For more information on how to connect your iPad to a Wi-Fi connection please use the following instructions:
http://www.apple.com/uk/support/ipad/assistant/wifi/
Please note: Your 3G network provider may also charge you for data used over a 3G connection. If you are unsure about your data usage policy please contact your network provider.
If we have not been able to answer your question, please e-mail ipcdigital@quadrantsubs.com.