Hi, I am having the same problem with a TeraStation HD-HTGL/R5 I purchased another NAS and moved several hundred gigs of data as the drive (raid 5) was showing signs of becoming full but despite this the TeraStation is now 100% full, all the trash boxes have been cleared just to be sure, did you ever get a resolution to your problem? from what I have read this seems to be a recurring issue with some of the Buffalo drives