Copying files across my network to external drive-permissions

Hiya

Ive copied 1tb of files across onto my HFS+ 3tb seagate external drive from a 2tb using USB and my Imac as a go between. Ive put the 3tb in my network and going through finder (shared) to copy across any new files im getting the below prompt.

"The operation can’t be completed because you don’t have permission to access some of the items" it works OK when I connect it to my mac via usb and manually do it but wont let me across the netowrk which is annoying as the mac is in a different room. It also will not let me delete any files when its across the network for the same reason

Ive checked get info on the drive and permissions are all ok with read and write..

Can anyone help me out here.?

THe drive is new and ive already ran it past disk utility and verified

Any help would be greatly appreciated