It could be down to "fair usage" so what I'd do is contact your ISP and see if there is anything they can do to resolve it.
Usually you can get a connection "doctor" which'll tell you where the problem lies (be it with your phone line, BT or the ISP)
If this is a continual problem then I'd recommend you switch to another provider, but if you're on a contract then it might be a little easier said than done.
Are you connected wirelessly? If so it could be that there's someone else nearby with another wireless router on the same channel. If they leave theirs switched off until they get home that could explain why it only happens at a certain time. Just a thought.
Hi plaffin looks like your broadband supplier is kicking you off the server if you are not getting a message,saying what the problem is,phone them and ask why you are being kicked off the server its up to them to give an answer,if they don't i think you need to give them the bullet.ive just got back on tonight this minute after being off all evening,i phoned and gave them a bit of hassle.Hope this helps.
aberdeen nut.