This is specific issue to IE 6 and IE 7
1. Have a presenter and share the desktop
2. Shift the screen share to Application - yahoo messenger chat window (to mention an application which i am able to consistently reproduce both in IE 6 and IE 7), the sharing shifts to this seamlessly
3. Now shift back to the Desktop share without stopping the publishing.
4. Repeat Step 2
5. Repeat Step 3.
Do the step 2 and 3 if you did not get for the first time to reproduce this.
The show items list has the name as Application 0.