I'm currently trying to make my site compatible with IE9 and there's already a major problem. I'm using Prototype 1.6.1 and it seems events won't be stopped with Event.stop anymore in IE9. I've read on Stackoverflow  Prototype 1.7 fixes that problem but I'm not sure if I should update. Deadline's coming soon and I don't know how much of a problem updating Prototype will be.
So here's my question: Is there a way to stop events in IE9 with Prototype 1.6.1
would you recommend upgrading to Prototype 1.7? Would you say there are some things that could be problematic?