Deleting GUIs does not always delete them?

In working out some memory cleanup of our project, I took a real close look at the dumpTextureStats(), and realized that numerous GUI graphics were still in memory. What I found weird about this, were that the GUIs had already been deleted! I ran a number of tests, and found that myGui.delete(); would work - sometimes. In the exact same situations, the engine would sometimes just not delete the GUI, and keep its images in memory.

I came up with a rather temporary and ugly solution for the time being, however I'm curious if other people are seeing this problem as well. If so, it's a pretty serious memory leak.

Here's my stopgap solution:

function superDelete(%objName)
{
  while(isObject(%objName))
  {
      %objName.delete();
  }
}