After my internet speed connection fell by 75% , i could find no cure or cause for it. More in hope that expectation i rang the AOL help line . After going through the usual stuff ( telling me to try turning off the modem for 10 mins etc) i was asked when was the last time i changed the ADSL filters. This was a new one on me , i assumed they lasted a lifetime.They were about four years old. I was told they needed to be changed every 6 months.After doing a bit of research i could find very little evidence to support this claim but decided to buy two new ones on the off chance rather than spend more frustrated hours on the problem . They arrived 24 hours after ordering ( AOL offered some free ones but wanted 10 days for delivery ). Much to my surprise after fitting them things returned to normal and the connection speed is less variable. It could have been just a local temporary service problem ( AOL denied any knowledge of such ), but the BT filters have impressed me.