i thought you were doing something different... hmm ?
anyways it sounds like something that will come only through time and practice... also the muting thing is a wise route to take... someone here said that i think it might of been jfrick... but if that's the problem i'd have to agree w/ the muting theory... often times i'll bring my thumb on my fret hand way the heck around the neck and be able to mute that way , but that is when i'm resorting to wild frenzy of frantically wide bends , w/ butterfly vibrato..
good luck man...
as for the sweep arpeggios , i've posted some stuff on sweep picking on the sweeping thread superhuman had a list that i echoed and elaborated on a bit... if you're barring strings when sweeping you gotta roll yer finger , if your in an (ex:) E minor triad on the first three strings say
9th fret E third finger on the G string , 8th fret G 2nd finger on the B string , 7th fret B first finger on the high E string , followed by a trill w/ your pinky to the 12th fret trilling off the 7th fret... you've gotta time each finger in terms on when you lift yer third finger it should be muting the G string as you're fretting the B string and so on... start w/ "three string" sweeps , then try 4 or 5 strings then try 6 or 7 if you've got a seven string
