What steps will reproduce the problem?
1. Built my own marker list (as shown in the attached screenshot)
2. Used for some period of time, icons displaying correctly
3. Over several sessions, started to see icon images get lost, despite the
fact that the original marker list is still there and that the labels remained.
4. The attached image shows the latest view...with all icon images gone.
5. Partial workaround seems to be to copy to a new worksheet...this helps,
although some of the icon images immediately start to go away.

What is the expected output? What do you see instead?
The markers should each have their image being displayed in the nodes.  Get
the red X instead

What version of the product are you using? On what operating system?
Using 3.0.2, Windows XP SP3, Java 6

Please provide any additional information below.