Hello
Smeck - welcome to the forum!
Your might want to provide some further detail, i.e. iPad 1 or 2, jailbroken, & iOS version; also, did this problem happen after some change/update and a new observation - just a few questions to hopefully help others to respond. In addition, does this happen on all websites or just a few?
Just a few other steps (which you may have already taken, if so my apologies) - double click on the home button and press on Safari, when the jiggling occurs tap on the X and then restart: if not of help, have you restarted and/or reset the iPad - if not give those options a try - good luck & please respond back if none of these suggestions are useful - good luck!