HTMLareas going blank in client overnight

Hi all,

my menus are based on HTML areas. If I leave a client running overnight and come back in the morning the menus are all-white. They still work if you know where to click and moving to the next screen everything is fine again.

have anyone else seen anything similar?

Client on Mac OS X 10.4.5/Java 1.5
Servoy Server 2.2.2 on Linux