What happens when you try this?
What OS are you using?
when I do this, I go to the next photo.
I use windows 7.
thanks for your response
Yes, the left-right arrows do tend to take you to the next/prev picture.
In some cases I have gotten left/right to change the values, but that may have been with the brushes/etc that had a "done" button associated with them.
For the Basic sliders, use the up/down arrows to increase/decrease the values.
I believe that there is now an upgrade available to remedy this problem.