Cannot delete file created in my share by other user? (10.0.2)

Scenario: I (admin) create an “Upload your files here” folder under my account. I share this folder with other users, giving them “create” rights and inviting them to upload stuff there.
I then process their files, moving them to their final destination and deleting the original.
This went fine with previous releases. However with 10.0.2, I am no longer allowed to delete the file. I cannot “reshare” it as well.
Is this a bug, or a feature? The file is under my user account, yet I cannot do much with it, as apparently the rights are assigned to the original uploader?