There is a couple things you could try, one would be to use lower textures, 128 x 128, that is if your have increased them higher since 128 is the default.
Another thing you could do is change the screen res from 1024 x 768 to a lower setting by editing the config file of your game.
If you do change the res you also need to change the image file associated with the menu, and background images as these will stay the same size as the originals even though the res is changed and will be streached across the screen.
http://forum.thegamecreators.com/?m=forum_view&t=48798&b=26