To clarify, 169.254.xxx.xxx is the default IP range that Windows falls back to if it isn't allocated one by either your ISP or by a router with DHCP capability.
The range is a reserved IP address range, as others are shown here:
http://tinyurl.com/6puut
If you have a router, then that would allocate IP addys using one of the ranges shown on the page above.
As I've never played with a STB, I presume you've tried rebooting it, maybe levaing it off for a while between reboots?
Sorry I can't help much.
hapless