CSS Cursor Disappears Until Mouse is Moved

Question

I have a large div that defines an image-based cursor in CSS using classes. On Chrome and Safari in OS X (and no other browsers), when the class of that div changes, the cursor disappears until the mouse is moved, then it shows correctly.

Example CSS:

.cursor-base {
  cursor: url('images/addeditblack.png'), auto;
}

.cursor-replace {
  cursor: url('images/replaceblack.png'), auto;
}

Is there some way to fix it in CSS or to work around it in Javascript?