My site uses custom post types for "events" and it also uses many plugins, so there is a bit of mess to clean up, but I don't know how.
Here are the two main problems:
1. Some events, not all, will not let me delete them. The trash link is not there, if I used bulk edit it give me: "You are not allowed to move this item to the Trash."
2. Some events don't even have an id number, any sort of edit link or even a checkbox by them.
There are many more similar glitches but I'll spare you the gory details. If anyone would like see a screen-shot of this anomalies I'll be happy to send them.