I've already done a factory reset to see if it fixed it although it hasn't helped. The error message is in the system log, as I checked it because I noticed it happening. When I get the error message I have no access to the internet although it doesn't say my line has dropped. I don't know what the light status is as I'm never near the router when it happens, although I am connected via Ethernet.

I've added the whole log from the last few days, although I didn't get one from before the factory reset :( (removed my ISP username from the posts though).

PS. Thanks for responding to me so quickly, much apprechated!

EDIT: One thing that has changed since this has been happening we've had a guest login (on the guest login), I reset the router hoping to test it but my brother let the guest login again before I had a chance to test, just wondering if this could have anything to do with it, as it's the only thing I can think of, I also got into contact with the ISP and they said the line looks okay, just to rule that out.

Got any ideas on what is causing this? Still happening, hoping to get the ISP provided router/modem out of the loft soon and give that a shot. I'm starting to get issues with the wi-fi telling me I've put the wrong password in, once I've given it a reboot it'll be okay, might try disconnecting the guest network soon.