Switching from mac desktop opens new windows (Ubuntu)

When I switch from my Mac apps (using cmd-tab or Expose) to my Ubuntu desktop it opens 2 new windows within the Ubuntu environment. Is this a Parallels issue or Ubuntu picking up some hotkey (i am relatively new to Linux!)

Thanks in advance
Zippy

 

Can you please attach some screenshots explaining your concern?

 

Here are three screenshots; before, changing, after. All I did was go into Expose/Mission Control (image 2) and then click on the PD window. The two Home windows appears then.
Command-Tab between the apps gives the same thing

 

Please, send us problem report and post its id here. For this make VM window active and in its Mac application menu go to Help -> Send Technical Data.

 

Here is the problem report ID: 192715345
Thanks in advance