I noticed this while playing Embodiment of Scarlet Devil, but it happens with all Touhou danmakus.
The computer usage is at 50% all the time and the ending cutscenes are slow and fails to clear the graphics or something. The different lines are written over themselves etc.
The gameplay works well, though, so this isn't anyway critical issue, but it is bit annoying.
Running with Vista and dualcore. I tried to run the game with XP and 98 compatibility and with administrator's mode, but they didn't change anything.
Edit. Updated drivers and changed graphical settings (from the Nvidia Settings Panel) helped.
