I'm using Firefox 1.5
...which appears to be rather unstable, although the crappy plugins I'm using could be to blame perhaps. Seems like no nifty new feature comes without 5 major regressions in the program.
Here is the official statement from Firefox: http://www.mozilla.org/security/history-title.html
Also, a warning has now come out for Opera .. apparently the same problem. Here is the story on Opera: http://secunia.com/advisories/17963/
I'm at 1.0.7