strange behaviour after volume and power cable replacement

i replaced volume and power cable in my i pod touch 4g,first time i tried i couldnt get the power button to work and only 1 of the volume switches worked,so unsoldered and resoldered the cable, now the power button works but the volume buttons are displaying a strange pattern of when you touch the volume button it has a mind of its own it turns itself down and when you touch the other button it stops going down but its not right,after the volume symbal leaves the screen a few seconds later the voice control screen comes up without me touching anything,and when i switch it off it sometimes switches itself back on, any help would be well appreciated