I am experiencing this as well. I am using composite video to my new 500.
Here's the mystery:
Toshiba laptop - win7 - IE 9 gives sound only, no video.
Same laptop - Firefox - all works ok (I have a different issue that I'll post in a different area)
Compaq desktop - win7 - IE 9 works properly - as does Firefox & Chrome.
Both machines have the identical antivirus/firewall (Zone Alarm) both are kept up with current security, et.al. patches.
Haven't tried full screen on the Toshiba in IE 9 as someone on a MAC indicated it might work (this forum)
Meanwhile I solved the problem. I bought new .apk for € 10,99 in de Play Store and installed it.
It is working now fine on my phone.
Van: pkittle firstname.lastname@example.org
Verzonden: zaterdag 15 december 2012 20:17
Aan: Harold Joels
<https://community.sling.com/index.jspa> Slingbox Answers Forum
Sound YES video NO
Thanks for using our Answers Forum! Since the Slingbox is working fine on your Compaq and on Firefox and Chrome on the Toshiba it would seem to me to be an issue with our plug-in that is installed into Internet Explorer. Since you have to install the plug-in for each browser something may have gone awry when that Internet Explorer plug-in was installed. I know of a link on our support site that should help with uninstalling and reinstalling the plug-in:
Hope this helps,
The Slingbox Moderation Team