[TYPO3] admPanel pencil puzzle

[Bing Du]

Hi,

Typo3 V4.0.4

Can anybody tell me why the pencil image
http://somesite.some.edu/typo3/gfx/edit_fe.gif shows up fine in page
source, but doesn't show up in the page itself?

I have 'page.config.admPanel=1' in the root typoscript setup and have
'admPanel {...}' in user/group TSConfig.  I can see the admin panel on the
page fine.  Just no pencils.

The tricky part is we use pubcookie single sign on for backend
authentication.  So if logon has never happened,
http://somesite.some.edu/typo3 will redirect to the university pubcookie
login page.  However, I've already logged on
http://somesite.some.edu/typo3 in another window of the same browser
(firefox), I think pencils should show up on http://somesite.some.edu.

If I go to http://somesite.some.edu/typo3/gfx/edit_fe.gif directly, the
URL changes to https://somesite.some.edu/typo3/gfx/edit_fe.gif and a
pencil shows up fine.

I'm totally lost now and would appreciate if anybody could shed some light!

Thanks in advance,

Bing