Eu estava com este problema no meu samsung S3 e encontrei esta solução num fórum. Testei e funcionou. Deixo aqui para ajudar quem tiver o mesmo problema.
Desculpem não estar na nossa língua mãe.
Fonte: http://www.transform...eycomb-ics.html
[SOLVED] .nomedia doesn't work under Honeycomb & ICS
The standard trick under android to "hide" image files such as book cover artwork or cd artwork from the Gallery app was to place a .nomedia file in the folder concerned.
However, for some reason this process has been buggy in the extreme on tablets. Well, I believe I have found the solution. It would appear that under Honeycomb & the ICS we have on our tf devices, the media scanning process only gets done once - when the system is first started. This means that all the artwork for books etc gets presented in the Gallery app even if there is a .nomedia file in the relevant folders/s. On many android devices, there is a setting that enables you to rescan your media. Or if you unmount and then remount an external storage card, the system rescans - but not on HC or ICS!
SOLUTION
Place .nomedia files in all the folders you do not want displayed in Gallery
Go to settings - apps - gallery
Clear cache, clear data, force close
Go to settings - apps - media storage
Clear cache, clear data, force close
Hard reset (cold boot) this will not delete any data
Next time you open Gallery it may not contain anything, but give it a minute while the system is still scanning the device & you will find that only the folders you want to be visible, are visible.
Result 
Editado por atena, 27 October 2012 - 12:49.
