I should have asked, are you running windows or linux? This is an option in windows that allows you to hide the file extension. The option is located in control panel>folder options>view tab. Then you uncheck the 'hide file extensions for known file types' box. I did this on my windows box at work and It screwed up my flash, because I had inavertently named initrd.bin to initrd.bin.bin. since the last .bin was hidden. But if you are running linux (as you should be) this could not possibly been your problem.