#1
Hello!
I've watched and read a couple of guides on how to mute unwanted noise, but they don't seem to be covering on what my problem is.
So, my problem is when I am playing palm muted notes (with distortion), and I move onto a different fret with my index finger, the lower part of that finger presses onto the higher strings, sounding like i am playing a horrible hammer on with the lower part of my finger.

For example: http://puu.sh/j9xMh/a44145bed2.png (Copy and pasting the ascii tab somehow messes up. Tab from here: http://tabs.ultimate-guitar.com/s/system_of_a_down/question_ver2_tab.htm)
In the above example, all of those notes are played in palm mutes. So at the 9th fret, my middle finger is playing that, but as I play the 7th fret when I press down with my index finger, the lower part of my finger would press against the higher a and c strings, producing a short ugly sound.
What's a good technique on how to prevent that?

thanks!

If im not too specific enough, please let me know.
#2
Does the ugly sound come when you pluck or just when you press down with your finger
#4
I would try just using the fret hand without plucking any strings.
sound out the notes that way until you can get it without the errors