User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.4) Gecko/20060608 Ubuntu/dapper-security Firefox/1.5.0.4
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.4) Gecko/20060608 Ubuntu/dapper-security Firefox/1.5.0.4

If I open a window in fullscreen mode, and hit <Alt>-<Tab> enough times to cycle back to the current application, the xfce panel will appear above my application window. 

Reproducible: Always

Steps to Reproduce:
1. Open two applications (terminal and firefox)
2. In one window, turn on fullscreen (Alt + F11)
3. Hold down the Alt key
4. Hit the Tab key enough times (should just be 2 times if you only have 2 apps open) to select the currently open application.
5. Release the Alt key
6. The xfce panel will now be overlayed over your application.

Actual Results:  
Shows bugs

Expected Results:  
Application should still be in fullscreen mode (i.e. panel should be hidden)

using Xubuntu