The JTable header does not show roll over effect for XP LAF. 

Steps to reproduce. 
1) Make a simple JTable . 
2) Set the LAf to XP.
3) Now roll over the mouse on the headers. 
4) Note that there is no roll over effect.
5) Now open Win XP explorer. 
6) Set view to detailed, so that the contents are displayed in a tabular form. 
7) Roll over mouse on the header and you will see the roll over effect.