Recently I upgraded to Extreme 105 with Comcast. I'm able to reach above that wirelessly but only for a short time. After about 30 minutes of using it the speed begins to drop until I reboot the modem. Any ideas what could cause this and settings I should check ? It usually only takes about a half hour before I can see the speed drop. It's always the download, upload isn't affected. When I was on a lower package (25 down but about 33 with PowerBoost) I never had any problems.