Hi, Elliot.
Without seeing the code I can't be certain, but this seems like a problem with collapsed map usage and a recently discovered bug in Camera.restore().
Can you answer some questions.
1. Are you using a collapsed map (toolkit.collapse_map or toolkit.collapse_layers)?
2. Are you using State.save() and State.restore() to switch maps and cameras in order to draw the grid?
It would help if you could provide a download link to your source.
Gumm