If I post these with wp-syntax
Well, you could post them without using wp-syntax.
wp-syntax is using
<pre> tags, which is what's preventing automatic word wrapping. WordPress is happiest when you write your posts as plain text. No formatting. If you need to add formatting, do it in HTML.
Of course, if you're posting actual code, then the word wrapping actually matters, doesn't it? In which case you don't want the page to add its own word wrap.
The short of it is that you can't have it both ways. If you use
<pre>, then you're expected to add your own word wrap, along with everything else.