Old Mavic Rims - Modern Tyre

I have a 27 year old road bike with Mavic rims. Recently I decided to get this old back back on the road. So I purchased Schwalbe Durano DD folding tyres. Hard to get on but did eventually. Ridden once but when riding the bike feels wobbly. Is there a chance that these modern tyres are not suited to old rims? The tyres are 700x25. The rims are Mavic 4 Open CD. Any views would be appreciated.