Yeah, it's been happening to me too. You target an object and when your in range your detailed surface scanner reports it is scanning with the rotating symbol next to it. Then it says analysing and then reports in the top right info panel that it has completed, but it doesn't report what the object is, but returns to scanning again.
It repeats the scan and analyse before finally reporting what the object is. Ended up scanning 30 odd object twice before they registered properly.
And also the discovery scanner requires operating at least twice or is very slow to report a lot of the time like the second poster says.