Hi Stefan,
Update for you....
After I got home I played around for a while and I think I cracked it (fingers crossed).
Foscam app - non connection issue over 3G, I swapped the camera IP address for my external IP address and hey presto, it now works on wifi and 3G.
I found that various people say different things, some say to connect using camera IP others say use external IP, external was winner for above app.
I will have to wait till I go work tomorrow to test from another computer using external IP but I have a feeling it will work.
iCam app - I also tested iCamSource with external IP and camera IP and they both work over wifi and 3G.
Over 3G both IP cam USB cam now only seem to have a 1-4 second lag, a much better improvment.
I think it was worse when I tried at my sister house because I remotely accessed my computer from hers to run iCamSource.
Will test 3G from near work too, I know 3G is not connecting to my wifi, but a just want to do a proper test
As my external IP is constantly changing (due to more reboots these days, port forwarding etc) I think I will sign up for DDNS and make life easier for myself
Should be receiving a Foscam FI8908W tomorrow, so I should have 1 USB and 2 IP cams running from iCamSource.
Will let you know how I get on.
Thanks