Obviously you have the divider height property set > 0
Check that the Divider Color is Not set to Transparent.
Failing that upload a small sample project that displays the issue.
Edit: Just to add ... the Divider is the CLV / Scrollview background color. If there is any undesired color between item/row views,
you can place all the views on a (correctly colored) Panel first , resulting in just a divider line between clv rows.