I'd recommend contacting www.mastercare.ie to see what they have to say about it. I'm a satisfied customer having seen them recommended here on AAM and have subsequently recommended them here and elsewhere to others. I'd bet that the cost of repair could easily make buying a new one a cost effective option. Seems to be the way these days with applicances etc. The door seal on our fridge could do with replacing for a while now but the cost of just the part alone would make buying a new appliance worth considering!
Agree totally with Clubman; our 18 month old microwave which cost over £200 had a problem with the turntable mechanism. Sharp didn't want to know, talked to a repairman here and he said it would be cheaper to replace.
We finished up with a Bosch combination oven which had a built in microwave with no turntable.
Don't forget that if you do buy a new one then bring the old one back for recycling (withing 15 days of purchase) for recycling under the WEEE rules since you are forced to pay for this anyway.
Thanks for your replys. We went out and bought a new one at the weekend and left the old one at the shop (thanks clubman!). It really annoys to me to have to get rid of a working microwave just because of a faulty latch but I guess that's just the way things are these days!