My 10Mbit has been doing it for the last few days also, always around the same time, between 13:30 - 16:00, it can cut out about 10-15 times. It doesnt seem to be heat related (at least in the case of the cable modem as its only just warm to touch).
Outages may only be small, but it means im getting kick off online games and my phone which use VOIP gets cut off or im unable to make calls.
LOL, i had a ping running so that i knew when my internet would come back on, and whilst typing this message, the connection has gone again. Its getting on my nerves. This outage whilst typing this message lasted 8 minutes