When re-editing: Lines breakes are removed in code formatting using Internet Explorer 7

Using Internet Explorer (v.7) the "code:xml" formatting is modified by the system after editing again the wiki item. The first save shows the formatting correct; using different lines for eacht XML element, but when editing the saved item again the XML elements are put in one big string, this results in horizontal scrolling in the browser. And is annoying when the Wiki item must be re-edited.

<metadata>
  <didl:DIDL ...>
    <didl:Item>
      <didl:Item>...</didl:Item>
      <didl:Item>...</didl:Item>
      <didl:Item>...</didl:Item>
    </didl:Item>
  </didl:DIDL>
</metadata>

Becomes after re-opening for edit

<metadata><didl:DIDL ...><didl:Item><didl:Item>...</didl:Item><didl:Item>...</didl:Item><didl:Item>...</didl:Item></didl:Item></didl:DIDL></metadata>

This is NOT the case with Firefox, so it might be a problem with processes running on the client.
However, many of my coworkers use the Internet Explorer and I cannot make them use Firefox.
Exery time an IE user is opening the wiki item for editing, the line separation in the "code:xml" formatting is gone.

The Item on the support page presents something similar for the new code macro: "Line breaks in new code macro are removed when edited inside WYSIWYG editor"
see http://jira.atlassian.com/browse/CONF-6183

Related issues to the code macro are found on http://jira.atlassian.com/secure/IssueNavigator.jspa?reset=true&&pid=10470&component=12361&resolution=-1&sorter/field=priority&sorter/order=DESC