Hi guys, one way to force it to refresh is by doing this:
1 - Go to the network options, disable the wifi connection (somethimes you have to wait a minute after doing this step before doing the next ones).
2 - Try to open the dlna folder (you won't be able to because it's missing) .
3 - Re-enable the wifi connection and try to open the dlna folder again.
(If it doesn't work the first time give it a few tries or reboot the TV with the wifi disabled).
Another alternative is this. When you open your dlna folder you can select "all files" or you can specifically chose "audio", "video" or "pictures".
If your video file doesn't appear when you select "all files" it can still appear when you chose "video", or vice-versa.
I know this sounds like you're just a few steps away of doing a rain dance but I hope this helps.