File uploaded to Scribd on every node edit

After editing a node that has a scribdfield with a value, the document is uploaded to Scribd as a new document during the save process. This results in multiple copies of the file in Scribd.

The problem is in scribdfield_nodeapi() during the presave op. Some check needs to be added before calling scribdfield_api_upload() to see if the file already exists in Scribd. Or, maybe some uploaded bool flag needs to be added to the field to keep track of whether it's already been uploaded.

Further, is it possible to delete files from Scribd? If the user uploads a new version of a document, should it replace the old document in Scribd? That's more of a process question, so maybe it should be a setting.