iPhone 4 resolution difficulty - @2x naming technique not working for button image

I have a button with an image set through interface builder. The original image is SearchImage.png and the high rez version is SearchImage@2x.png. I'm absolutely sure that no typos were made, and the higher resolution image is indeed开发者_JAVA技巧 exactly twice the size (ie twice as tall, twice as wide) as the lower resolution image, yet the office's iPhone4 still only loads the low resolution image.

Does anyone have any ideas what the problem might be?

I have read all the relevant Apple documentation.

Thanks! Tristan

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Just assign the image property "SearchImage.png" and include both SearchImage.png and SearchImage@2x.png in your main bundle and it will load the correct image.

See https://devforums.apple.com/message/233916#233916.