Network drive disconnects but is still accessable

I have come across an issue that I have not seen before. If anyone out there has seen this please let me know if you found a fix. I have a Lacie Storage server attached to the network. The folders are mapped to the network’s desktops. When someone tries to open a Microsoft Word document from the mapped drive it will not allow it and give a permissions error. What gets me is that any other document format will still open(adobe,autocad etc), this only affects Microsoft documents. If you look at the properties of the mapped drive after you attempt to open a document it shows that the drive is disconnected, but you can still access it normally, except for Microsoft documents.