Weird Bug

When the below code is already in the textarea when loaded the <? echo 1+6; ?> is no where to be seen in the source view. its as if it is stripped out

<? echo 1+6; ?>
<form action="/dn/sendEmail" method="post" name="contact">
<p>
Name</p>
<p>
<input name="name" type="text" /></p>
<p>
Email<br />
<input name="email" type="text" /></p>
<p>
Message<br />
<textarea name="message" rows="5"></textarea></p>
<p>
<input type="submit" value="Submit" /></p>
</form>

Which should display as the below in source view

<? echo 1+6; ?>
<form action="/dn/sendEmail" method="post" name="contact">
   <p>
      Name</p>
   <p>
      <input name="name" type="text" /></p>
   <p>
      Email<br />
      <input name="email" type="text" /></p>
   <p>
      Message<br />
      <textarea name="message" rows="5"></textarea></p>
   <p>
      <input type="submit" value="Submit" /></p>
</form>

Instead it displays as:

<form action="/dn/sendEmail" method="post" name="contact">
   <p>
      Name</p>
   <p>
      <input name="name" type="text" /></p>
   <p>
      Email<br />
      <input name="email" type="text" /></p>
   <p>
      Message<br />
      <textarea name="message" rows="5"></textarea></p>
   <p>
      <input type="submit" value="Submit" /></p>
</form>

Hence the bug im reporting is that this part

<? echo 1+6; ?>

/

<? echo 1+6; ?>

Is totally stripped from the textarea. When I submit the form it is also missing from the $_POST which leads me to believe ckeditor has removed it.

I confirmed this issue using an out the box sample of ckeditor/_samples/replacebyclass.html

Just copy the first code I provided above into the textarea and load the page.

Please advise as I will not be able to use this great piece of software while this issue is in place.