The looping working fine in one browser but not another suggests (to me) a problem with
the other browser rather than the web site or my gpu. So I will try to have some e-mail
conversation with the slider's lead developer (I've had e-mail discussions with
him before). I hope to get adequate information from him to submit a good bug against
Firefox. This is likely to take a while. If and when I submit a bug, I'll post its
number here.