The recipe I found wanted red wine vinegar, and also added some faffing about with cornflour to thicken it.

One of my colleagues claims to know about this kind of thing and says that sweet and sour sauce is very much a make-it-up-as-you-go-along sort of thing, so it wouldn't be surprising to find that no two recipes agreed even slightly :-)

Mine's not from a recipe, just from trial, error and reading the ingredients list on cook-in sauces.

It uses white wine vinegar because malt vinegar doesn't work. I don't believe I've ever owned red wine vinegar.

I've developed this recipe, after much trial and error (not disgustingly inedible error, just not coming out quite the way I wanted it to):
1 can pineapple chunks in juice
2 tbsp soy sauce
2 tbsp vinegar (malt vinegar works fine for me)
2 tbsp ketchup
1 tbsp cornflour
about 1/2 inch chopped ginger
salt and sugar to taste if necessary (depends how sweet the pineapple chunks are, really)
Prepare in advance in a bowl; mix in the cornflour fully. If I add ingredients gradually while cooking, it goes lumpy and doesn't come out right. Cook the sauce at the last moment, in a hot frying pan with oil. Stir it constantly until it changes colour and goes thick. Then serve it straight away (with battered deep-fried quorn chunks, if you're me!). mobbsy and razornet seemed to like it a lot, and to me it is indistinguishable from sweet and sour sauce from a (nice) Chinese restaurant.