Hello Finalzero,
I am currently having similar problems with the folder view structure on both my TV in one room and the Xbox in another since I refreshed the Multimedia Share Settings on my 320L. In my case, they now both show nothing under Folders, though under All Files they will show every single video in an exhaustive list, making browsing a pain. Though I can view music via artist or album, this is also a real pain as there are hundreds of both and probably wouldn't result in a "thinking about it" screen for ages (reading ... reading ...) if I could see and select the folders that I filed them under.
I have had my 320L for a few months and it was streaming to all (TV, Xbox, PCs) fine until I began to add music folders to the shares. I have no idea why - pretty lame if you cannot even update/refresh the device without causing problems...
Did you find a solution to your folder problem? I see that there have been plenty of views of this thread though nobody has offered a remedy yet...