Graphic Errors, Mapping is incorrect.....SOS

One month ago I got a brand new PowerBook 15". 1.67, 1024 SDRAM, ATI 9700 128MB, Combodrive. The Laptop is the one from my dreams, the deal is that since it arrived it displays this really annoying problem wich is the defectuous mapping of the OSX enviroment. The clock on the upper bar usually is mapped with something wich I don't recognize, the Dropmenus from the upper bar also appear transparent and the options become visible only when I pass the mouse over them. Another sign of the malfunctioning is the Trash Icon in Dock that flickers when mouse is over the dock ( if I minimize other windows, then is the Icon most to the left of the dock area that flickers.....
The strange part comes now, when the computer gets some activity (warms up I guess) all this problems seam to fade away almost completely, like the laptop was optimized to work properly only when its hot...... strange stuff going here!
I do know that My laptop is still under warranty, but I am stationed in Portugal and here even sending it in can be problematic..... if anyone can help.... thks ;)