Conflict with upload module / file attachments

On a Drupal 4.7.5 site I'm running, enabling this module prevents any user other than user 1 from uploading files using the upload module.

Original situation:
File system set to private
All users can perform some file uploads - i.e., pictures to profiles, video files under video module, attaching images under image module, etc.
Access rights for upload module set correctly
But only user 1 can actually attach files to nodes

Any other user can:
- Browse to file
- Click Attach
- See whilst still in edit that the file is listed as being attached
- Submit the node

But then the file disappears - not listed in the node nor is it there when they go back into edit, nor is it in the files directory

I accept this may not be an issue with remember me, but disabling that one module solved the problem for me.

Regards

Patrick