Getting Error 0x80070027: Disk is full

Also bought a ReadyNas Duo V2 recently, same disk full problem when trying to copy a 100 folders each containing a dozen Mp3 files. Will also be returning this unit unless there is a fix soon. Unusable as it is now, gives error after copying only a few folders, there is no pattern that I can see. Can retry copy and it copies beyond where it failed before until the next failure. Had a V1 Duo that had none of these problems. Also V2 had no SqueezeCentre addon as standard, had to go searching around for that too! Very disappointed with this product.