I've had the same experience! Well sort of, I think it's related to the experimental zoom I enabled. Trying to track down how to reproduce so I can open a bug, but it's sporadic for me. Other than that, I'm pretty happy with the browser
Guess I need to submit a bug report.
Edit: apparently Bugzilla requires passwords longer than 10 characters - wow! At least the that's the error I got (password too short) when I tried to sign up. Seems excessive.