heez10 wrote:Strangely enough it works on some galleries but in some it does not!
I don't know if this is the reason or not, but if your galleries have different picture sizes, it could be that one gallery has photos that are larger than those in another gallery of yours, and if there isn't enough margin space between the photo and the viewer's browser edge, then it won't work.
I found that with photos 1024 pixels wide, say, that there has to be a fairly large margin between the photo edges and the edge of the browser, for the arrow-keys to change the picture to the next or previous one...