IPhone 4 Wi-Fi connects, doesn't load anything

Question

Hello there,
Up until a week or two ago my Wi-Fi was working almost flawlessly on all my iDevices.
Now however, both my iPad 2 and iPhone 4S have issues loading anything through my home Wi-Fi network. They both identify the network, and about 80% of the time they can connect to it. But it refuses to load data (Safari hangs for ages until it tells me it can't load the page, apps that use the internet forever load etc).
Here's a list of the things I've done on my iPhone to try and solve the problem.
TROUBLESHOOT /// EFFECT
Turned iPhone on / off /// Sometimes no effect, other times the internet works for about 20 seconds before being unable to load data again.
Renewed lease /// Usually no effect, once or twice it worked for a minute or two.
Reset network settings /// No effect at all.
Turned Wi-Fi on/off /// No effect.
I have Virgin Media 100mbit internet, so it uses the "Superhub" that is a modem and router in one. Here's what I've done on it to fix it:
TROUBLESHOOT /// EFFECT
Lowered Wi-Fi Speed (Old: 300mbps New: 150mbps) /// No effect.
Manually selected a wireless channel /// No effect.
Reset router entirely /// No effect
Reset Wi-Fi (pressed button on the front, D/C's and then reconnects WiFi devices) /// Worked for about 20 seconds, then nothing.
As you can see, I have no idea what is causing the problem. Sometimes messing with the router gets a VERY temporary fix, and sometimes messing with the iPhone does.
I should mention I'm connected to business broadband (BT phone line) at the moment, and it's working fine.
The Wi-Fi has always been set to these standard settings:
802.11 mode:
Up to 300Mbps
802.11N Band:
2.4Ghz
I haven't troubleshooted on the iPad 2 (It's not mine) but it had problems at the same time as my iPhone 4.
It's awkward because it's hard to tell what's causing it. On the one hand, it could be my router/hub because both iDevices wok fine on the secondary network. On the other hand, it could be the iDevices, because my laptop connects fine.

Answer 1

What fixed it for me was resetting the Touch, then restoring (an 8 HOUR PROCESS!!!!!).
WHen I disable security in my Wireless router, I can connect without problems to all the internet / web services. I still haven't been able to connect from an outside w-fi connection, but they are probably blocked in some way, even though I do connect.