I have download the song "Suteki Da Ne", put it in my game and tried myself. However, I do not have such a problem with it. The game does not crash when I scroll over it.
Please try using the program which our forum recommends - UltraStar Deluxe WorldParty 11.10
. Perhaps this helps.
If you are already using it, then please try de-install and re-install the game. Sometimes this solves the problem too.
If all that does not help, then please post here again.
By the way, did you accidentally change anything in the .txt file or in the folder? This could also be the reason.
I have not downloaded the song "Real Folk Blues" myself. Unfortunately, I do not know what you mean with "Once having chosen this song it continues playing from the preview." Sadly, I do not know why the lyrics are not working in your game. If you renamed anything or changed the .txt file, then it would explain everything...
Is the video file of the song a .mp4 file? If yes, then this might be the reason why it does not work. I think the ultrastar game program does not support that file ending. I have this problem with the Vampire Knight song too. The video does not play because it is not an .avi file. There might also be a problem with the resolution. For more information, please read this post