That's very strange. Could you try rebooting your iPad to see if that makes a difference, maybe you have exhausted your RAM with other apps running/etc.
To reboot the ipad2, hold the power button until you get the slide to power off slider, slide it. Wait until the ipad is completely off, then power back on using the power button.
If this doesn't resolve the problem, then please let me know, along with your firmware version, and any other info you can think is pertinent.
The crash dumps are also always really helpful if you can provide them (see here, or search online on how to find them:
http://aplus.rs/apple/how-to-find-crash ... ta-and-xp/)
Thanks for letting me know of your problem!,
Raf.