Please describe the problem:
Buttons don't always know that your mouse pointer is hovering over them. Clicking on it is then impossible.

Steps to reproduce:
1. open the application Synaptic
2. it takes a little while to load... quickly move your mouse pointer to the big "Search" button while it is still loading the package database

Actual results:
The button doesn't get highlighted. You have to move away from the button, and then go back to it, in order to be able to click on it.

Expected results:
The button should become highlighted, and clicking on it will be immediately possible.

Does this happen every time?
when following these steps above: yes

Other information:
I'm not sure if it's a Gnome bug, but I can't think of anything else.
I am using Ubuntu, and this has always been a problem (I started using Warty, and the problem is still there in Feisty)
It is also happening with other buttons.