Unable to delete folders off of a Network Drive.

I am having difficulty deleting folders and files (in 10.3.2) off of a Windows server (not sure what server software it is, it's either NT or 2000), and was wondering if anyone could help.

Essentially, I try to delete a folder, and it says "The operation cannot be completed because the item "<insert name here>" is in use." Sometimes it gives me an error that says I don't have sufficient privileges.

A little more information:

In the Finder, it says that I can read and write the folder, and in applications like FUGU it says I own the folder, and others have the ability to read and write and execute as well.

I tried using Terminal and the RMDIR command, and it says...
"Directory not empty"

When you look at this folder with a Windows machine, there are files in the folder that are hidden, and have a '._itemname' but those are not able to be deleted either. If I use an applescript to show invisible files in the Finder, it doesn't show those files to me, only on the windows machine. If you try to delete the file in Windows, it says, "You have committed a sharing violation."

Any ideas or suggestions would be appreciated! Thanks!