Here is photo evidence of Ian's mischief. Thankfully, he hadn't fallen into the vacant space yet, because that is always especially traumatic for him. The blue bottom isn't solid, and has a network of bars underneath it, which becomes a tar pit for little Ian, where he flops around until rescued. While I was taking pictures, Ian was willing to demonstrate how he does it -- I thought he had been slipping his little fingers under the end and prying it up. He actually just yanks on the middle of the sheet and the end flips up. I think we can prevent this by just removing the sheet.... hope it works.
Another solution is to buy Ian a real crib, with a real mattress. This crib is my current favorite and is the only one I have liked consistently. I like that it has really simple lines and is Espresso color (though the picture looks blackish). It is convertible, but that doesn't matter to me. It has great reviews online, but I would love to hear from anyone else who has it. Or anyone who has opinions on this type of crib. What did you look for in crib? What do you love and hate about your own? I figure if we wait nearly a year to purchase a crib, we had better get it right. And that kind of pressure has made this process take months longer.