Staff able to save to redirected desktop despite only having R/L/R+E permissions

[PrimaryTech]

As per the title really, all staff have a redirected desktop that they only have Read, List Folder Contents and Read and Execute yet they can still save to the desktop. I have the same settings on my students and this works fine, users cannot save to desktop or delete icons. I've checked RSOP and I can't see the staff being members of any other groups that would give them access. Any help would be gratefully received, this hasn't been a problem before but we have a couple of new teachers that believe in saving everything to the desktop, despite being asked several times not to.