form with backgroundimage and transparency problem when i show or hide a label.

Question

I created a gui with a backgroundimage, its a non rectangular shape image with some transparency in.

then i set a transparencykey, cause i want everything outside the border of the image to be transparent.

Inside the border of backgroundimage i have created some labels with no background, and then i hide some of the labels

This all works fine..

But when i want to show the hidden labels. For a second i can see whatever is behind the background of the label (for example: my desktop).

So my question is:

How can i just show the label without for a second see through the label? (its very important cause i show and hide labels allot)

My idea(pure speculation):

To set a transparencykey isn't a good idea, maybe there is another way?

I hope i explained it well, if not feel free to ask :)