E/GeckoConsole( 5039): [JavaScript Error: "TypeError: lastNode is undefined" {file: "app://homescreen.gaiamobile.org/js/page.js" line: 613}]

I can reproduce it sometimes although it is very difficult :)

please add 

if (originIcon && targetIcon && this.olist.children.length > 1) {  

in 

https://github.com/julienw/gaia/blob/fea94acf33d741986510c72fd42a9ef238d1581f/apps/homescreen/js/page.js#L583