Maybe you change some properties such as the Picture box size
and do not update it. Make sure you're calling
System.Windows.Forms.ScrollableControl.AdjustFormScrollbars
on your panel. Also, check up all other
AutoScroll...
properties.
[EDIT]
For example, you have
Panel picturePanel
, and it is a parent of you
PictureBox myPicture
.
Panel picturePanel;
PictureBox myPicture;
myPicture.ClientSize = new Size(xSize, ySize);
myPicture.Image = (Image)MyImage;
picturePanel.AdjustFormScrollbars();
—SA