PDF cover images are incorrect

[waynegraham]

When a PDF is attached to a page, it's cover isn't always associated with the object. Need to debug on what's going on (and why incorrect images are getting used).

[waynegraham]

This code takes the first attachment that is a PDF. This is fine, except when you have added an attachment (e.g. you replace the existing PDF in the page). However, WordPress treats the first document (which has been removed from the page) as it's first attachment.