I see no problem with youtube videos, cnn.com, intellicast.com, etc. No problem in iceweasel, also no problem in chromium-browser. Possibly the problem is with some specific site(s)?
root@imerabox:/# apt-cache policy flashplugin-nonfree iceweasel chromium-browser
flashplugin-nonfree:
Installed: 1:3.2
Candidate: 1:3.2
Version table:
*** 1:3.2 0
500 http://ftp.us.debian.org/debian/ unstable/contrib amd64 Packages
500 http://http.debian.net/debian/ unstable/contrib amd64 Packages
100 /var/lib/dpkg/status
iceweasel:
Installed: 17.0.6esr-1
Candidate: 17.0.6esr-1
Version table:
*** 17.0.6esr-1 0
500 http://ftp.us.debian.org/debian/ unstable/main amd64 Packages
500 http://http.debian.net/debian/ unstable/main amd64 Packages
100 /var/lib/dpkg/status
chromium-browser:
Installed: 26.0.1410.43-1
Candidate: 26.0.1410.43-1
Version table:
*** 26.0.1410.43-1 0
500 http://ftp.us.debian.org/debian/ unstable/main amd64 Packages
500 http://http.debian.net/debian/ unstable/main amd64 Packages
100 /var/lib/dpkg/status
20.0.1093.0~svn20120405r130901-0.sidcution.2 0
500 http://packages.siduction.org/experimental/ unstable/main amd64 Packages