html>body .sidebar li {
margin-left:-4em; } /* not seen by IE6 */

html>body .sidebar li {
*margin-left:-1em; } /* seen by IE7 */

.menu1, .menu2 { background-position: 0 1em ; background-repeat:no-repeat; padding: .3em 0 .3em 1em ; margin: .8em 0; }
html>body .menu1 { background-position: 0 .6em ; }  /* not seen by IE6 */
html>body .menu1 { *background-position: 0 1em ; } /*  seen by IE7 */

http://www.evotech.net/blog/2007/04/ie7-only-css-hacks/#star