Wifi Woes

[Flatlander]

So I have a Virgin Media SuperHub downstairs broadcasting as Wifi1 but it doesn't quite reach parts of the bedrooms upstairs. So I bought a mains extender kit, the 'base' is pluged in right near the S/hub and connected to the S/hub with a LAN cable, and the repeater is upstairs broadcasting as Wifi2.
It works, occasionally, but it's driving me nuts because Wifi2 just keeps dropping for no apparent reason.
When I bought the kit I assumed it would just work, but Wifi1 (login at 192.168.0.1) and Wifi2 (192.168.0.2) seem to be interfering with eachother somehow. The wifi printer is unreachable unless I turn off Wifi2.
Am I doing something wrong? Wifi1 covers downstairs nicely, and Wifi2 covers upstirs nicely, but they just don't want to play nice together.

I know there are special forums for this stuff but I'm hoping you know me well enough to use 'words of less than three syllables'.
(I have read that putting the S/hub in modem mode and attaching a decent router is an option but I'm not sure it would reach upstairs sufficiently because of location problems.) I have changed no settings apart from setting passwords. Plugging in a LAN cable to Wifi2 works nearly all the time so it seems to be a wireless problem.
Manual

Thanks in advance.

[chalsall]

Originally Posted by Flatlander

Am I doing something wrong? Wifi1 covers downstairs nicely, and Wifi2 covers upstirs nicely, but they just don't want to play nice together.

Make sure the two devices are configured for different (non-overlapping) channels. For example, 1 and 7.