Ok, here’s the latest on my problems with Real Player.
After writing the original post, I tried my Netbook and found I was having the same problems. However, the same Netbook, connected to my work’s wireless network, would work fine. Conclusion – the problem was with my router or ISP.
Time to dig out the router that O2 sent me and I’d never used…. connected that up and…. Real Player worked! So, it was my Netgear router.
Over the weekend I’ve been exchanging various emails with Netgear and, after escalation to some more senior engineers, the problem has been resolved. And it was fixed by…. downgrading the routers firmware. I was obviously being a bit too keen and I was on the latest firmware.
Anyway, it’s all now working and I’m happy once more.