Question: Internet Explorer 9 was released today, and I decided to check a few Magento sites we build in the last couple of months to see if everything continues to work with the new version.

But unfortunately it doesn't. I came across one particular problem that is caused by the version of the prototype library which is shipped with Magento, version 1.6.0.3.

It looks like the cancelling events in eventhandlers isn't working.  

For example, if you try to log in to a Magento shop, and just leave the login and password fields empty, IE9 submits the form even if there were errors, and the errors disappear after the refresh.  

So that's quite a big problem I think.

So my question is: how can we deal with this problem? I see a couple of ways to deal with this:

* Wait for Magento to release a new version with fixes
* Upgrade the prototype library to the latest version which probably already has fixed the issue
* Mess around in the existing library and try to fix the bug in there

Waiting for a new Magento release isn't a good idea because it probably will take a few weeks before there is one, and because it will cause a whole lot of other problems if you are running a very old version of Magento.  

Upgrading to the latest prototype library is probably the best idea, but will everything in Magento continue to work with the latest version of prototype, does anybody has any experience with this?

So what's everybody's opinion about this problem?
Any ideas other than mine?

Answer: 
Solved: <http://www.alexanderinteractive.com/blog/2011/10/solving-the-ie-7-ie-9-magento-prototype-validation-bug/>
I spent a couple days on this, and discovered the only thing that truly works is disabling things at the form level. This should solve all your problems.
I've updated the `prototype.js` file to 1.7 and so far it's correct. I dont see any errors. If you apdate and find errors please notify!