Adding a fix for the inability to set the point line width to 0. It's a bit of a hack, but it seems like an acceptable workaround.

jquery.flot.js

@@ -2092,6 +2092,15 @@ Licensed under the MIT license.
                 sw = series.shadowSize,
                 radius = series.points.radius,
                 symbol = series.points.symbol;
+
+            // If the user sets the line width to 0, we change it to a very 
+            // small value. A line width of 0 seems to force the default of 1.
+            // Doing the conditional here allows the shadow setting to still be 
+            // optional even with a lineWidth of 0.
+
+            if( lw == 0 )
+                lw = 0.0001;
+
             if (lw > 0 && sw > 0) {
                 // draw shadow in two steps
                 var w = sw / 2;