Nokia N900
Maemo 5
Version: 3.2010.02-8.002

I am trying to download and install applications over WiFi but it doesn't seem to be working.
I can connect to my WiFi network without any issue and view any website l choose, however, when l go to download and install a Maemo application nothing happens. I can view the full download list on the N900 and select any application to install but once it runs its check it just says "Downloading <file size>" and that's it. It doesn't make a difference how big or small the file is nothing happens.
I have found that if l do this using 3G then everything works perfectly. My only issue is l don't want to be downloading 7mb files over 3G as it will cost me a small fortune.
I have used the Nokia Software Update program to update my N900 to the latest version and have also reinstalled it using the Nokia suite as well. Any help to fix this issue would be greatly appreciated.