I've created a list with more than 80 fields. To lay it out more clearly I grouped the fields in multiple contenttypes. As soon as there was more than one contenttype Sharepoint showed a dropdown-box on top of the editform where my users could switch between fieldcategories.
When I accidentally deleted my editform.aspx I remained calm because I knew I could recreate it using SharePoint-Designer. Altough recreating the editform.aspx worked, the result is almost unusable. There is no more contenttype-dropdown and the fields are unsorted. When I add a new field to the list the editform doesn't get updated.
The only option I can see at the moment is to rebuild the list from scratch... which would take days. :(