Urgent recommendations to all Bento users who are not in the habit of doing so:
Check the Bento Forums regularly (link on the sidebar) for any known issues, look at recent user posts, and report all technical issues there as well.
These forums are moderated by Filemaker employees who have extensive testing facilites and personnel and are not afraid to use them. We don’t have any resources like that at BentoUsers.

Let me repeat the most recent issue:
Before you migrate from Mobile Me to iCloud or otherwise turn on on iCloud,
do this:
Make sure you have Bento 4.06
Launch it.
Quit Bento.

After that, you should be ready to surf the new Clouds.

Since Mobile Me will be available until June 30, 2012, I personally am not in a hurry to get OSX Lion and iCloud. But since there are very few issues which have been reported in the Bento forums, I have to assume that Bento is generally ready for the transition. That doesn’t mean that the problems reported here on BentoUsers are not real. But they are not the norm, but rather horrible bad luck.
Still, let’s all keep our eyes and ears open…