Recently acquired a Slingbox Pro (known to be functioning fine!). Plugged it in, it didn’t want to see the network. Wasn’t the cable, the same one worked fine on the PS3.
Didn’t want to reset itself at all.
Turns out the power supplies burn out quickly; and thankfully I also acquired a Slingcatcher which uses a similar power supply (5A instead of 4.5A). It however has a sticker saying “DO NOT USE WITH SLINGBOX PRO”.
I figured I’d try it since it was only 0.5A difference, and my Slingbox sprang to life after one more reset. Apparently it is quite a common problem.