[Al Skierkiewicz]

Mark,
If you had not changed anything and it had been working for a year then I would start out by looking outside of your installation. A call to the provider might show that they are now limiting your uploads or bandwidth. Either of these restrictions will interfere with your upload of video. It is possible that the router or modem have failed but unlikely. You can bypass the router easily enough but you will need to know what the log on info for your provider is. (they may also require some background software to log on without the router.) Just remove the connection between the router and the modem and connect your computer in place of the router. Be careful that some modems require a turn around ethernet cable instead of the standard cable. Your provider may have docs on the modem and connections on their website. Once connected try to log on and when you are connected try to upload a sample file.
If you call tech support they are likely to ask you to check for common problems that affect the modem so I will mention them here. Look for the addition of cell phones and other wireless phones near the modem. If the router is wireless and you haved changed it's location, suspect it may be interferring with the modem. I am trying to install a new Linksys wireless router and it interferes with my modem here.
Look for additional noise on the analog video on the cable the would indicate a bad cable coming to your house. Remove and reconnect all cables to the modem and router. They may have become tarnished or dirty in the past year and a reconnection will clean the surface of the connections. Look for devices that may have been added to the cable like a DVD or VCR that might be putting noise on the line. Disconnect any of these devices and check your upload again. Many consumer devices are not entirely shut off when the power button is pressed.
Hope this helps.