Render quality suddenly changed? last week I tried rendering with low resolution quality. Then I switched to 'HDTV 1080p' preset and it rendered well for some time (rendering took cca 4 minutes per image). 

Today I tried to render again. I've checked preview and it looks OK (preview takes up to 2 minutes to render), but when I click actual render button, it gives me a poor image with rendering time 0.25 seconds.

I don't remember changing any settings, but obviously something has changed? I cannot seem to find the reason. 

Here is the preview:



Here is the final render:



Settings: (cycles render):



Help :(

Thanks in advance, Gregor
I found the problem. I have previously made a animation out of images in sequence editor. When I clicked render, the computer did not do any rendering, it simply loaded already rendered image.

I fixed this simply deleting all the time strips @ Video Sequence Editor. Now it does surely take up to 5 minutes for one frame to render. :)

Cheers for all the help!