Troubleshooting question -Cable Internet

Ok for months now I have been doing a run around with Linksys and Comcast, I dont know what to do to figure out where my problem lies and get it resolved.. The problem is at night time my internet connection drops about 2-3 times a week. At first comcast came out and checked the line outside at the box before running into the house and determined there was a low power rating and line noise.. they have supposidly fixed this.. now they are claiming its my router. I have contacted Linksys to see if I could try reflashing my firmware but they dont carry the firmware software.. They said to contact Comcast for it, I did and they point me to here but it says file cant be found when I try to download it.. Im out of ideas as what to do to figure out why my internet keeps dropping at these random times at night.. Ive had more appointments for comcast people to just have it working during the day when they come out and say nothings wrong.. Figure you all being the smart bunch of engineers and such may know how i can figure this out.. Thanks! BTW its a Linksys WCG200 Gateway..

Maybe you can convince your cable company to lend you a stan-alone cable modem (without integrated router). Then you would probably be able to see if it's the service or your equipment.

My experience with Comcast is that if you don't use one of the cable modems on their list, there will be problems. My installer had no problem installing my modem (not on the list) but told me up front, I'd likely have problems. He was right, it had constant problems. I wound up junking my first buy and getting a listed Tosheba PCX2000. A separate wireless router completed the setup.

Thanks for the replies, looks like I will end up trying thier modem, end up renting it to see.. Luckly I still have my Linksys BEFW11S4 lying around here somewhere so I wont be completely SOL..