This is strange. at google's help page says that we can use class="notranslate" to mark a block of text that we don't want be translated. In my tests it worked great, but once I've added it to this forum, google would quit translating once found that class. For now I've removed that class and added some javascript that should display untranslated text for code blocks.
Let me know if you have problem with it and with performance.