We're just going to have to agree to differ on this one Dave. I don't think it is really
that contrived.
The only problem I really have with the colonists not finding the spaceship earlier is that, even if they didn't have the resources to check everything out in person, they should still have had access to very very very detailed satellite mapping (whether images or spectra or whatever) that should have shown up something as obvious as the spaceship.
On a related note, how did the Nostromo find the alien ship in the first place - was it a distress beacon? I can't remember, but if that was still running then IQ's had definitely dropped while Ripley was sleeping

:evil: