I didn't think to take a screenshot of this, but the following happened.
1) I Selected two planets and played them.
2) While the points were still being moved around, I went to the exploration grid and clicked on a tile. An Exploration event asking me to pick a reward came up.
3) While I was looking at that event, Science points finally moved into place and a technology was completed. The technology announcement appeared BEHIND the Exploration event. The Exploration event was uninteractable; it didn't respond to mouseclicks.
4) A TINY SLIVER of the button acknowledging the Science completion was sticking out from behind the bottom edge of the Exploration event, so I clicked on that. The Science announcement closed and the Exploration event display worked normally.
It might be worth putting modal windows into a queue if a modal window is already active. Also, it might be worth allowing the user to select an option that says "I know how the game works, just move the points instantly once I play my planets, please."
