Following on this ticket, can I reproduce the problem by cut-and-paste from an Email?

Here is an Email content added here using CTRL/V:

	Here we go: <container::test> what does this do in FCKEditor?
	Also try
1. Do this
2. Do that
   root.exe
   > .x blabla.C

and so on ...

OK, this did not create any problems (the <,> were converted as expected into &lt;,&gt; .

What about copying from a Web page which is wrong in the first place? For example, this ticekt's document revision from Thu, 2008-09-18 06:59 would give:

Got output:
FGMO
Info in <tgeomanager::weight>: Computing analytically weight of FGMO
Info in <tgeomanager::weight>: Computed weight: 1111.200497 [kg]
</tgeomanager::weight>

Nope ... it did also add proper tags for <,> ...

One more try. I created this page which contains the infamous HTML.

Characters such as lt; and gt; cannot be placed in text verbatim or it will be recogized as HTML tags. However, there is an ambiguity whenever placed with <pre> </pre> blocks as below:

 a = (int) (5 > 2 && ( 6 == 1));

and more importantly, this pseudo-tag  would be
arbitrarily interpreted by Browsers.

the tag would not be seen in Firefox (would ignore) including the wrong HTML this way but the Drupal HTML source would show it as

 a = (int) (5 > 2 && ( 6 == 1));

and more importantly, this pseudo-tag <tag::test> would be

The FCKEditor escaped the <,> properly but ignored the false tag. Now, this is not a problem for Firefox (I can still edit this page and add more information like this setence which was added after saving the previous).

Fromthis point on, IE would chock on the hidden tag <tag::test> and editing would even scramble the blocks (some parts are not showed at the proper place). I cannot edit the page anymore with IE (Firefox is fine).