Tooltips flicker on OSX

Question

I'm creating a cross-platform GUI using JavaFX 2.0, and some of the controls that I use require tooltips to be displayed when the mouse hovers over them. I've got the tooltips displaying fine on my Windows 7 machine, but on OSX (10.7.3) the tooltips appear and then dissapear immediately, and the only way to get them to display again is to move the mouse off the control and then back on.

Is this a known issue with tooltips under OSX, or is there something special that needs to be done?

Many thanks,

Joseph.