JQuery & qtip: IE7 is choking on sizzle line 1782

I’m using the jquery qtip extension and IE7 is choking on line 1782 in the jquery source. Anyone have any ideas?


...
	preFilter: {
		CLASS: function(match, curLoop, inplace, result, not, isXML){
			match = " " + match[1].replace(/\\\\/g, "") + " ";

			if ( isXML ) {
				return match;
			}

			for ( var i = 0, elem; (elem = curLoop[i]) != null; i++ ) {
				if ( elem ) {
					/* 1782 */if ( not ^/* wtf? */ (elem.className && (" " + elem.className + " ").indexOf(match) >= 0) ) {
						if ( !inplace )
							result.push( elem );
					} else if ( inplace ) {
						curLoop[i] = false;
					}
				}
			}

			return false;
		},
...

What version of jQuery are you using?

We stopped using qTip at work after upgrading to jQuery 1.4.*
qTip still requires jQuery 1.3.* - perhaps that’s the problem?