I use SyntaxHighlighter Evolved to show code on my wordpress sites. One one site using the TwentyTwelve theme, everything works as expected. However, on another that uses Virtue, all the code is shifted down one line when line numbering is turned on. I saw one comment on this, but I couldn't figure out what they were changing. Has anyone else seen this, and if so, is there any easy fix in css or similar?
Edit: to follow up, I realized that the shift does not occur in Chrome but only in Firefox. A typical occurrence is here.