Not quite. For English speakers, it may be easier to imagine there are three homonymous but not synonymous words "über" in German. The one in question roughly means "about", and CANNOT be used with dative, just with accusative. The one with dative means "above". And the third one is with accusative once more and means "over".
(Grammarians would probably beat me to pulp for this explanation, but as I said, I think it's easier to imagine this way for English speakers.)