I use LinkStation and Quad LT-H90-LAN connected by LAN 10/100.
Movie Files copy from DVD or Rip to ISO no problems.
You try to resolve the problem by Initialization LinkStationis in the Menu Maintenence.
Initialization is a reset procedure that restores all settings back to the default, out of box, configuration. All configuration, users, groups, and backup jobs are lost, but actual data and shares on the hard drive are NOT lost. If you want all data to be erased, erase the drive. Specify whether the LinkStation shall keep its administrator password after a initialization or whether the password should be reset to the default password (default password is password). Press the Apply button once you make the selection. Press the Restore button to begin the initialization process; this will restore all settings to factory defaults but will NOT erase the data on the hard drives.