I just don't get it...

[slimjim]

Proof that the Destiny can find the ships:
http://www.youtube.com/watch?v=QioXOJh4WJQ - 2:46 - they detected a bunch derbies that are a days trip away in FTL. Surely they can detect massive, operational ships that are WAY closer than 10 hours FTW.

apparently that derbies was giving of radiation

[hedwig]

Really I can't image most other computers on the planet would still be working after 30 years of neglect

But this is stargate. Computer stuff works just fine after hundreds or thousands of years of disuse. Works every time an SG member pushes a button on some ancient stuff that's been unused for that many years.