Once an attachment is added to a conversation or progress discussion, there is no way to completely remove the attachment from the project. Even if the conversation item is deleted, the attachment remains in ‘files’.
File & content management is an important piece of our project tracking, and it seems strange in the extreme that files/attachment can be added to conversations/progress but cannot be removed.
I am having the same problem. It seems that images (logos etc) from some of our users email signatures are being captured under conversations as attachments. Therefore when I go to files to try and pull up a document it is loaded with all of these logo posts that are in there over and over making it extremely difficult to sift through to find actual documents that I need. There seems to be no way to remove these from the conversation time line.