I previously had an issue where iPlayer would freeze every minute this issue is related, however where as my previous issue was unlikely to effect anyone, this has more likelihood that it could.
Over the last few days I had the issue where iPlayer on the V6 (PC iPlayer was fine) would freeze every few minutes, but only during the evening. off peak times it was fine, so I assumed it was down to local contention and buffering.
The main problem is that iPlayer on the V6 will regularly do a dns lookup and then freeze while it waits for the result. If it doesn't get a result in 5 seconds it then tries the secondary DNS. So if a primary DNS lookup fails then the picture will freeze for 5 seconds (or longer if secondary fails).
So if you find iPlayer on the V6 or Tivo freezing, check your DNS settings as that could be the issue.
Ok this time I was stupid as I'd accidentally set my secondary DNS in my router (superhub in modem mode) to 18.104.22.168 instead of 22.214.171.124. At peak time it would have a problem with 126.96.36.199 and switch to the secondary causing devices on my network to try the secondary 1st..