Ive seen this mentiones earlier here, but te solutions seems to have been missing wp_footer() in the template.
I have the problem that
< br /> & lt; ? < br />
gets added in the first line of my highlighted code.
Every line gets a
<br \> at the end, and at the last line i get a
?& gt;< br />
It seems like the tinymce is trying to escape html/php. Even though I am using HTML mode, not Visual.
Heres a link to a "live" post showing my problem.
I also have trouble with lots and lots of
& gets added to my code. But for now i cant reproduce it, it only happens on my older posts.