Newline HTML problem of rdoc 3.6.1

I was trying to make a document for my code via rodc3.6.1 on Windows 7,
and I found there’s something wrong in HTML output after I clicked on
method to toggle the source code.

Here is the screenshot:

I am wondering why it generates extra newlines between every line in my
source code. However, when I changed OS into FreeBSD, it just fixed.
Here is the screenshot:

I have been confused by this problem for a long time. I tried to google
it but in vain finally. Is there anyone having the same problem just
like me? How to settle?

(I am sorry, English is not my mother tongue, if your can hardly
understand what I am saying. I’ll try my best to explain clearly in
reply below.)

Thanks a lot.=)