Can't Access Only One Networked Drive Out Of Four

I have two Windows 7-64 computers on ethernet. The other computer has four physical hard drives, one partition each, C, D, E & F, all shared, and with "Everyone" given full access on the Security settings.i can write files from my computer to that computer's drives C, E & F with no problem, but whenever I try to write a file to that computer's D drive, I get a popup window titled "Destination Folder Access Denied", with an error stating, "You need permission to perform this action". (I get analogous messages if I try to delete a folder, etc.)I can read from that drive fine, and I can transfer files to it using UltraVNC.I've gone through all the sharing and security properties of that drive, and I believe they're all identical to the other drives that cause no problems when I write to them.