I'm getting lock ups as well started maybe a week or two ago. I'm running Chrome 5.0375.55 on Windows 7 64 bit.
I'm having the same problems. I have to use firefox for BS otherwise Chrome freezes up completely. I was curious if this was common or not. I also have that issue with the shadow of "Open a New Tab". I was worried it was a sign of a virus.
Just as an additional data point, I'm using Chromium 5 on Ubuntu 10.04 (all 64 bit), and I have not experienced a single problem on BS.
It is working right now. However, it has been sporadically working. Although mostly not. Hopefully you guys got it.