Thanks for getting in touch!
We aren't aware of the bug you're describing.
However, we do have a counter measure for crashes in the GL when entering the background thread.
In your application can you call the ShinobiChart method setIsEnteringBackground: when entering & exiting the background thread?
More information on this property can be found in the Documentation folder of your Shinobi download.
If you are still seeing the issue, could you manipulate one of our sample apps to replicate the crash and send it to us at email@example.com?
As I'm struggling to reproduce your crash and it would really help us identify the source of this issue.
Let me know if you have any questions.