In the comments sections:
Gravatars/avatars that were replies to parent comments were getting squished. The width was not setting correctly in Firefox.
min-width: 60px; will fix that.
If min-width is not set, the parent Gravatar width is fine, but the width for the children Gravatar replies were getting pinched down. It may be a parent DIV property that is squishing it, but min-width placed directly on the .gravatar appears to have cleared it up. To whoever originally authored the comment CSS, it may be better to look at the parent DIV properties but I did not dig that deep. It appears to work fine now and I have not witnessed a drawback.
You may want to include this in the next update.