I disabled the “Jetpack Comments” feature, and that resolved my problem in all browsers. I left the other Jetpack features that I wanted activated.
This situation occurred using the latest release(s) of WordPress and the Jetpack plugin. The theme is twentytwelve.
It seems odd that such an integral feature will not work (for me), but I am new to WordPress.
I just wanted to let folks know what I am experiencing.
Any suggestions appreciated.
Thank you and all the best.