selector {
	height: 10em; /* min-height for IE. Must be declared above declaration for other browsers! */
}
selector:empty {
	min-height: 10em; /* min-height for browsers other than IE */
	height: auto !important; /* Override previously declared height for browsers other than IE */
}

or even simpler:

selector {
	min-height: 10em; /* min-height for browsers other than IE */
	height: auto !important; /* Override declared height for browsers other than IE */
	height: 10em; /* min-height for IE */
}

selector {
	height: 10em; /* min-height for IE. Must be declared above declaration for other browsers! */
}
selector:empty {
	min-height: 10em; /* min-height for browsers other than IE */
	height: auto !important; /* Override previously declared height for browsers other than IE */
}

Only tested in Safari 3, Opera 9.5 and Firefox 2 (all Mac OS) for now, but it should actually work. If you run into any problems, please provide some feedback.

Crossbrowser min-height

css, ie

CSS