quite common with certain aircon systems, try changing the pollen filter (if it has one) then there are various deodorising kits you can buy to spray in the intakes/blowers...
OR the cheap way out is to get your self a smelly spray turn the aircon onto inside circulation and spray under the passengers foot well, that way the smelly is dragged into the aircon and out the other end so to speak smelling a bit better that curry powder.
Bacteria and fungi build up on the evaporator ( the part of the system that gets cold) and need to be got rid of, thats what the smell is!
You should have your air con serviced by a qualified engineer. dont just take it to some back street garage, most of them dont know what theyre doing!
Air con is not covered by a normal car service.
what year is your CORSA , early or late? the pollen filter is in two tottaly different places...early under the scuttle panel, late ones behind the glovebox
on my 2002 corsa (doesnt have air con though) the pollen filter is behind the scuttle below the windscreen, you need to remove the plastic covers around the wipers etc to gain access
HI I have had problems with my 04 Corsa smelling from the air vents.I too have been to Vauxhall garage and they said the air con needed regassing .I had it done and no difference.they then tried pollen filter,again no difference.The latest was another pollen filter an disinfect the pollen filter box area.NO good again.I have noticed over the past 18 months since trying everything that the smell comes even if the air con is switched off!The smell comes and goes and all i can do is appoligise to unwary passengers.I wouldnt go to the expence of service air con try the pollen filter and keep a spray can in the car.Its cost me �s so no more.