BBC staff member Jon (iPlayer Host) has stated on their forums (linked above) that they have fixed issues people were having using the BBC iPlayer on the PlayStation 3 console.
To quote: Kalel2008: As soon as I read on the Web site that you can play videos from the iplayer on the PS3, I was so excited untill I found that it was not true.
dosyman: You can, but it's an unofficial site. http://www.ps3iplayer.com
Steve9719: There's an even more official way to get the iPlayer working on the PS3. Simply visit the Wii version of the site: http://www.bbc.co.uk/iplayer/bigscreen/
Jon (iPlayer Host): We're putting in a fix soon that should make everything better (for the PS3 at least). Update: We've put the fix in and it should now work correctly.
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