The extender logs on under a different user name (eg: MCX1). So even though you have everything looking good on the PC (Under your PC user name), you have to copy the library files from one user name to the other for it to look the same on the extender.
Go to C:\users\PC USER NAME\AppData\Local\Microsoft\Media Player and copy the following files: CurrentDatabase_360, LocalMLS_0, LocalMLS_1, LocalMLS_2, LocalMLS_3, LocalMLS_4 and wmpfolders to C:\users\MCX1\AppData\Local\Microsoft\Media Player.
Then what you see on the extender will be exactly the same as what you see on the PC. Create a couple of shortcuts from the desktop to these locations to make it easy to do it again.