|I'm with StuartS and Derek; A higher/current/wattage rating would do no harm, as long it is a 'proper' power supply, designed purely for laptops.|
In addition; Why did you need to replace the original power supply? Had it failed completely?
I've known folk replace the power supply, when the fault was actually a bad connection on the laptop itself (not a repair to be carried out by the inexperienced).
Perhaps the new unit is faulty; some of the very cheap chinese imports can mis-labelled, of very poor quality - and indeed, dangerous.