Editing Blocks, the second field is modified.

The second field is under:
Show block on specific pages:
Here I have to put <front> in order to specify that my a Block should
appear at the front page.

Of course I have excluded this field from CK according to the message (sorry in German)
"CKEditor: Die ID zum Einschließen oder Ausschliessen dieses Elements ist admin/build/block/configure/block/7.edit-pages"

Also fields used for php statements, explicitly excluded from CK, get a lot of disturbing break tags,

So in "multifield" Forms, where some text fields are excluded from CKedit and others not, we get this problem with the unwanted tags.

A fix that worked for me (as posted in http://drupal.org/node/1098586 #2 ) is to replace in ckeditor.utils.js

$(this).find('textarea').each(function() {
with
$(this).find('textarea.ckeditor-processed').each(function() {

wow!
I use "*.edit-pages" in the Global CK Profile to exclude the second field. No excludes in the other
profiles

$(this).find('textarea').each(function() { is at line 375 (not 355, as posted in 1098586 )
Drupal is Version 6.20
CKeditor 3.4.2 (the editor, not this module)
Theme is Garland. happens also with other themes.

the <br/> (or <p>..</p> depending on the settings) tag appears immediately when I press save (so its javascript)

This problem doesn't occur with Version 6.1.2 or replacing in ckeditor.utils.js
line 375 with $(this).find('textarea.ckeditor-processed').each(function() {

For the Theme 960 Robots It doesn't occur if I first save the block with an empty second field, and afterwards I edit it again inserting <front>

Did you run update.php ? the problem appears only after running the update.
I hope this info helps.

@dczepierga
Nice, it works without problems, thx