Browser history navigation bug in Chrome and Safari

I've been seeing some odd behavior in Chrome - occasionally browser history would get hosed pretty badly. When I noticed the same issue navigating the website I'm working on, I ended up spending a bunch of time trying to get to the bottom of the issue. Initially I suspected it was something wrong with the site, but I was eventually able to create a stand-alone repro for Chrome (v3 and v4) as well as for Safari (v4). I suspect this might be a WebKit thing, which both browsers share, but I don't know enough to be certain.

The problem seems to occur when you spend time moving around fully ajax sites that contain one or more iframes (I've seen this on GMail as well). In my case I worked around this issue by not using iframes but I imagine that's not always possible. Anyways, this is now Chromium bug 30693.