To be quite honest I am guessing your on one of the ASAM's that are overbooked. We have a growing number of customers who are getting int./no synch issues in relation to oversubscribed exchanges. Now this is not really news as Eircom has been aware of this for some time, and only recently have they released a List of new stations around ireland to help relieve the congestion (
Damien Mulley » Blog Archive » eircom to enable another 100 exchanges, 120k more people can avail of broadband) because that is what it really is, as you say, you come home in the evening and jump on and get lower bandwidth than say in the morning. I partly blame the sales staff as they are just throwing anything and everything to the public to get the almight euro and sign up new customers, and couldnt give a damn to the rest of us who have to shoulder the weight of new people taking away the bandwidth. So to sum up, no you havent done anything wrong and I doubt your equipment is in any way faulty, its just a matter of to many people in your area. Hopefuly this will be resolved but I cant give you a date or time. If it gets any worse I would suggest changing to a new ISP, even though you would be jumpered in the same exchange, Eircom provide racks/ports for other ISP to rent and perhaps they can suit your needs better as they are on a seperate line(so to speak) and dont compete with eircom customers.