Easy way to see if wifi is secured is download inssider2 its free and will show all wifi around you and their level of security
The default wifi pass is on the back of your router (home hub) and can be read by any one hope you changed it
Download Inssider2 for free from http://www.metageek.net/products/inssider/download
Might be wiser to just do a factory reset. This will wipe any "untoward" firewall/port rules that could of been sneakily set.
My Brother (Ex BT engineer) found a sneaky folder on his comp with 20gb of pr0n in it. He was wondering why the net slowed down so much. He was being used as a server.
Many thanks to all the kind people that replied. All info will be tried. I aint to hot on forum sites etc so I hope all respondents get this note of thanks. Cheers Scropter