Thread:Extension talk:WYSIWYG/SyntaxHighlight (Version 1.0.8.10 - r115163) using GeSHi - Generic Syntax Highlighter/reply

Have you tried to create completely new page containing only your syntaxhighlight definition in order to see if there is something else on the original page which may cause wysiwyg parser to get confused?

What is the code as plain text you tried to put inside tags?