The root cause seems to be a new DRM setting: even if the device has been used in the US since installation, you get an error about the device not being authorized for use in the USA.
"This Slingbox was not originally designed to be used in the USA. You may not be able to configure this Slingbox for some devices in this new location."
To make matters worse, Slingbox charges $29/per incident for support, even if you're still under warranty but past the first 90 days. I find it offensive to have to pay for support for a problem caused by their software update. They seem to feel free to ignore any problems that their software is causing for any customer with a box more than 12 months old — if I were more cynical, I would think that this is their version of planned obsolescence.
So, if you wanted to replace the Slingbox with a similar device, what other options exist? Is there anything open-source, or at least made by a more consumer-friendly company? I hate to buy another piece of hardware, only to have it disabled by the manufacturer after the warranty runs out.