...I finally have hit the "Oh shit, my Game Boy Pocket truly doesn't have a processor that can power all the fun stuff with LSDJ" wall.
I was experimenting with making a noise kick, wave bass and the "spacey percussion" from this LSDJguides video (http://www.youtube.com/watch?v=CCAKmOepYvs) and LSDJ started really messing up as I was editing. Characters from previous screens wouldn't go away, highlights would get stuck as I scrolled and other weird anomalies. I stopped playing the pulse channel and it was back to normal.
So, it only took me about 3 or 4 months, but I think I'm about to outgrow the Pocket.