One thing people may want to check while the problems are actually occurring is whether there's a network problem between you and the SB server.
Open a command line window. First, try pinging the server ("ping www.scubaboard.com"). If the connection is working well, it should be reporting a response time of less than a couple of hundred ms, and generally well less than that. (Also, depending on the OS, you may have to hit something like ctrl-c, ctrl-d, ctrl-z or ctrl-break to get it to stop pinging.)
If ping is successful, try traceroute ("traceroute www.scubaboard.com" or for Windows users, "tracert www.scubaboard.com"). This will slowly show the list of routers between you and the server. Generally, most people will show 10-20 'hops'. If it hits 30 hops, things may be going in circles and you might suspect a network problem. Some routers you're passing through may not respond to traceroute requests, and you can generally ignore those, but if there's no response data after a certain hop, there might also be an issue.
PS. For your own protection, some Internet security types recommend not posting traceroute results in a public forum.