diff -Nru a/jQuery/src/core.js b/jQuery/src/core.js
--- a/jQuery/src/core.js	2008-09-08 11:58:56.159963300 +0800
+++ b/jQuery/src/core.js	2008-09-08 12:02:42.139734300 +0800
@@ -917,7 +917,7 @@
 
 			// If we're not dealing with a regular pixel number
 			// but a number that has a weird ending, we need to convert it to pixels
-			if ( !/^\d+(px)?$/i.test( ret ) && /^\d/.test( ret ) ) {
+			if ( !/^-?\d+(px)?$/i.test( ret ) && /^-?\d/.test( ret ) ) {
 				// Remember the original values
 				var left = style.left, rsLeft = elem.runtimeStyle.left;