This has been a bit of a problem for me, especially when using the mobile version of Newgrounds.
I would just be scrolling down the page on my music to check out reviews and things of that nature, but as I'm scrolling down with my thumb just sliding across the screen not even tapping anything, it somehow picks up the little voting bar and it registers me as rating my own song as 0 stars, totally destroying song's ratings. Yeah, I could just change it to 5 stars, but the damage was already done as I practically rated on my own work.
Call it a mistake on my part, but I only ask of you to try this out for yourself on your own phone and see if it is also happening to you.
There should be an option in the settings that disables the ability to add a rating on my own submissions. I could imagine several people having a problem with this as well.