Problems with internet connectivity
It's common to experience trouble connecting to Second Life when using a dialup modem, satellite internet, or any other form of internet access that's not DSL or cable. This article explains why.
The entire Second Life world is streamed to you over your Internet connection while you're inworld. Dialup connections simply do not have the transfer speed or response time to present a viable Second Life experience.
Satellite connections suffer from very long response times (on the order of several seconds) that do not effectively allow Second Life to provide fast back-and-forth data transfers. These connections may be able to serve web pages quickly and download single files fast, but as their documentation usually reveals, they're not designed for online games. Since the data transfer rate of most satellite connections is not dedicated (it's shared among all users), many providers also have "Fair Use Policies" that limit download speeds once the amount of data transferred reaches a certain amount -- an amount Second Life can reach within hours.
Recent developments in wireless internet access designed for rural locales suffer from the same problems as short-range wireless networking: They're prone to interference and typically don't provide a connection fast and stable enough to provide good Second Life performance.
If your internet connection is not cable or DSL, you can attempt to diagnose Second Life based on the error messages you receive, but it's likely your connection itself may prevent Second Life from running properly.