I've recently discovered that the oven in our new house is NOT at all accurate. Which causes big problems for me (and potentially for you, if you are trying any of my recipes!). The oven seems to be running about 50 or more degrees cooler than I set it too.
I have now purchased an oven thermometer and plan to make the fruit crumble again soon, so that I can determine exactly how long to cook it and at what temperature. Since it took about 35 minutes in my oven, which was probably NOT at 350 but rather around 300 degrees, it may cook MUCH faster in yours if you set it to 350. Please keep an eye on it and test the fruit for doneness after 20 minutes or so.
Fortunately we have only lived here since July, so any of the recipes older than July 2010 should be fine.