I'm thinking that a few additional parenthesis might be in order:
Code:
WHERE ((DataOraPlecare >= @DataOraPlecare) AND (DataOraPlecare <= @DataOraSosire))
	AND
	((DataOraSosire >= @DataOraPlecare) AND (DataOraSosire <= @DataOraSosire))
	AND
	((tab2.IdTip = @TipAutomobil)  AND (tab2.TipCombustibil = @TipCombustibil))
If it was a table aliasing problem, it would be a different error.

-tg