Why is my rendered animation different to what I see in the 3D view? I’m fairly new to Blender, although I’ve managed to put together some simple animations. 

I’ve made a simple ‘fruit machine’ with three wheels. Everything plays as expected in the 3D view, but when I render (whether to a sequence of .png images, or to a video) I’m getting a different result. The animation lasts for 600 frames. Everything starts off fine, but at frame 450 (for example) the rendered image is different (in the way that the second wheel is rotated) from what I see in the 3d view when I scrub the timeline. 

In the 3d view, I have ‘render only’ set in the display menu.

Is there something obvious I should be checking? I can post the .blend, if someone would take a look.

(Cycles, in v2.77)
You have two UVMaps on the object where the fruits are mapped to. See this screenshot:



At the moment in the UV Maps section, UVMap_wheel02 is selected, and gets displayed in the viewport. But the other map, UVMap_wheel01, is set to be the renderable one (the camera icon behind the map indicates that). That means, if you don't manually override the UV map to be used, Cycles will pick the one which is marked as renderable, so the first one in your case. If you select the first UVMap in the editor, you see this in the viewport:



If you want to use more than one UVMap in Cycles, you can use the dedicated UVMap node to grab a map by name:



Or alternatively you can mark the UVMap_wheel02 as renderable by clicking on its camera icon in the UV Maps section.