Weird colour problem with Real Video and Skype

[mike cloaked]

I have a Dell Inspiron 530S desktop with an Nvidia graphics card.
The hardware is at
http://www.smolts.org/show?UUID=pub_f3670c10-289f-4e85-804b-60babb27fb23

The machine runs F8 fully up to date and has kmod-nvidia installed.
The desktop is KDE3.5

Almost everything runs well and without any problems - but for a long
time there has been a really awful colour problem when running Real video
and Skype.

Two examples of the problem are on the screenshots at:
http://tinypic.com/view.php?pic=mhvk1t&s=4
http://tinypic.com/view.php?pic=20ggy84&s=4
These were obtained by going to the test page at
http://service.real.com/test/
and running the videos - it does not seem to make any difference installing
a different version of Realplayer.
I have the same setup on a different machine with different hardware and
not running kmod-nvidia and there is no problem with colour with the same
tests.

Flash video on web pages is fine and I am not aware of other colour issues but
I have been unable to fathom out how to fix this problem.

Does anyone have any hints as to what I may do, or a workaround, or
suggestion as to where I might look to fix this?

-- 
mike