Images More Info Section blank

Hello,

I am new to Macintosh, but now I am pretty much used to it. To the topic, I am photoshopper and recently I found the "Get Info" seems to have a bug which initally shows up the information of the image correct but next time onwards, it turns up blank.

Preview:

Initially

http://i.imgur.com/oziMMIY.png

When I do it again,

http://i.imgur.com/UtTJfZT.png

I don't know if it's bug or not but I find it inconvenient..

Thank you.