EDIT: IGNORE ME I AM A COMPLETE IDIOT!!!!!
Thankyou for the reply RC, but i managed to work it out in the end.
This afternoon nothing was making sense, the connection was totally random and i was about to throw the PC out of the window when i discovered a phone T'd into the internet line just after the wall socket that didnt have a filter on!!!! Hence the totally random connection loss. God damn i wish i'd checked that earlier!
Still, hope it bloody well works now, looking good so far 15 minutes with all computers connected!!! WOHO!!!!
Cheers guys