The original Syntaxhighligher plug-in does not work well in IE with fixed width themes. Specifically, Syntaxhighligher does not add the horizontal scrollbar correctly for IE. But in Firefox 3, the horizontal scrollbar works. I am using the iNove theme, if that makes a difference.
The scrollbar issue in IE was originally the reason I attempted to use the Syntaxhighligher-plus plugin.
The Syntaxhighlighter-plus plugin does not display the horizontal scrollbar in Firefox 3. Also the numbers are 01, 02, etc in FF. The scrollbar appears correctly in IE.
Perhaps these two plugins can be combined so that the best of both is available to IE and FF users.