With the final version of the Linux flash 9 plugin I'm able to watch the first
segment of NBC.com's videos, but no other segments. Access to the other
segments is provided through a javascript link which seems to successfully
cause the flash player to try to load something, but nothing happens after that
brief "loading" message.

Weirdly, if I leave my browser sitting on the page it will sometimes start
playing the segment I wanted hours later.

Other users seem to be having similar problems with NBC.com:

http://www.adobe.com/cfusion/webforums/forum/messageview.cfm?forumid=72&catid=61
6&threadid=1232055&highlight_key=y&keyword1=nbc

http://www.adobe.com/cfusion/webforums/forum/messageview.cfm?forumid=72&catid=61
6&threadid=1216963&highlight_key=y&keyword1=nbc

I also confirm the problem with CBS.com, though it seems to be related to the
opacity of the flashplugin rather than whatever's going on with NBC.com:

http://www.adobe.com/cfusion/webforums/forum/messageview.cfm?forumid=44&catid=18
4&threadid=1234122&enterthread=y

Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1) Gecko/20061024 Iceweasel/2.0
(Debian-2.0+dfsg-1)
Kernel 2.6.19.1

FWIW, this also happens with the latest Iceweasel available to me: