🚀 go-pugleaf

Hello,
Who could explain to me what happen in my JBuilder3.0 application.
I have two JPanel :
the left one with 9 JButton.
the other to display animation or single image
6 JButton are  used to display animations which consist:
    Stop the thread if isAlive
    load images in array of image and put them in a mediatracker
    start a new thread which animate
3 JButton to display scaled map or rotated map with AfineTransform...

My questions are:
When i press succesively the 6 JButton the first time loading is slow, but
the second time and other it's instantaneous.
every time i press on a JButton the memory regulary growth.

When i push the 3 other JButton sometimes appear the following message:
java.lang.awt.OutOfMemory
at.java.awt.EventQueue.dispatchEvent(EventQueue.java:258)
at.java.EventDispatchThread.run(EventDispatch.Thread:68)

What happen and how can manage the regular memory growth/
System.gc() don't  change anything ?.
can i flush() image after each utilization?

Thanks for all
Jean-Pierre Ballet