You are using a Fixed Layout (which specifies a fixed height for the image area) but are embedding the gallery into a container whose height changes depending on the size of the user's browser window so on a screen of limited height (such as a laptop), there are many images in the gallery that are being truncated and are not being displayed in their entirety.
Set useFixedLayout="FALSE" for a gallery that will dynamically resize based on the user's browser window size.
Also, your page has several errors that should be fixed to ensure greater compatibility when being viewed in different browsers.
You can validate your page using the W3C Markup Validation Service and then fix the errors reported (such as the missing </body> and </html> tags).
SimpleViewer Support Team