Ok. So this is weird. I am not sure exactly what the problem is … As long as you have the most-current download of Fiji and have updated your Java installation. There were some issues with Java versions and ImageJ (an example here) - you can read more about that here and how to check your versions, etc.
Would you be able to report to us the exact system you are using - as well as the exact version of ImageJ/Java? (for the latter… just click on the status bar)
The only other thing we could try - is if you post your image here for us to try to open and manipulate as you did to see if we can reproduce the bug you are seeing.
One final thing to be aware of… be careful with the way you open an image in Fiji. On the whole - I usually go through Bio-Formats just to be ‘safe’ so the metadata is all read in correctly…
Hope this helps a bit!