Wordpress editor removes all the linefeed characters with WP-Markdown and Syntax Highlighter evolved

I have WP-Markdown and SyntaxHighlighter Evolved wordpress plugins installed.

The issue is that when I write the code, and click the "Update" button, I have the code reformatted.

[ruby] 
class Foo  Bar 
    def hello 
        puts "Hello World!" 
    end 
end 
[/ruby]

This is the modified code.

[ruby] class Foo  Bar def hello puts "Hello World!" end end [/ruby]

There is no change without the [ruby] tag.

class Foo  Bar 
    def hello puts "Hello World!" 
    end 
end

How can I prevent the code modification? I tried following actions to get the same results.

• I checked Disable the visual editor when writing
• I tried Xhanch My Advanced Settings plugin.
• I tried CKEditor For WordPress
• I used Safari and Chrome web browser.