A few weeks ago, using 3.5.1 on Fatcow using Bouquet I added slides with no problem.
Now I'm on Bluehost with Twenty-Twelve and no other plugins. I upgraded this morning to 3.5.2, then found I can't add slides. I tried and failed to roll back to 3.5.1, so I can't see if the new release of WordPress is the cause of the problem.
It can't be a theme or a plugin issue. I've added slides in the past so it is unlikely to be a user issue. Bluehost is the WordPress #1 recommended host so it is not likely to be a host issue.
Please check if 3.5.2 necessitates an update to the plugin.