Well, I spent another couple of hours fooling with this thing, and I'm done.
I think I've now tried literally every combination of settings on my wireless router and the RC9800i just will not connect. To add insult to injury, it connects fine (but with not enough signal to actually download anything or even set the clock) to my neighbours unsecured router (nice of him to leave it that way so I could try it out).
The only conclusion I can come to is that the RC9800i does not like one or more of the features of my router. The router is a 108MBps device, which I've alreads had to slow down to broadcast in 802.11b and g for the remote, and is also a MIMO device (multiple transitters for far better range and signal strength). I'm certainly not going to shut these features of for the darn remote and sacrifice connectivity of my other devices.
So, what am I left with? Essentially a great looking, but barely functional universal remote. It doesn't recognise half (literally) of my remotes and honestly the color display is a waste as some genius at Philips decided to make almost all the buttons grey. Without WiFi, no media streaming, no EPG and it won't even set the clock.
Time to see if I can return the thing, or failing that try to sell it on eBay and at least get some of my money back.
I used a Pronto TS-1000 for years and will now have to consider what to do next. I'm thinking about a TSU-7500, but after this experience I'm not so sure. If you believe the hype, the RC9800i looks like a great deal, paticularly as you can pick one up new for <$300 and if you can get it to work, great, but my advice would be that unless you can verify the somebody has sucessfully used an RC9800i with the wireless router model you intend to use, don't buy one.