windows completely disappear when "minimize" button clicked

[user1]

I am using ubuntu 10.10 ubuntu netbook edidtion - I installed from an 
ubuntu alternate cd, then I installed kde which I have been using for  
several years - but then something did not work so well any more in kde
(kmail and klipper) so I switched to ubuntu netbook edition (after having 
heard Shuttleworth's words).

My netbook has worked well, but now when I click on a minimize window 
icon the window closes down (alt+tab works when I do it in the proper 
virtual desktop - I have 6 running).

I use the option to minimize windows a lot and then I need to be able to 
see all the minimised windows in the panel.

The minimize window function still works ok in my kde desktop?