Processing indeterminate text output on screen

There are errors in Processing that cause output to be placed off location. Run this example:

boolean sw = true;

void setup() {
size(480,480);
}

void draw() {
fill(0);
textSize(24);
text("Draw this message repeatedly", 10, 30);
if (sw) text("Draw this message once", 10, 60);
sw = false;
noLoop(); // remove or comment out after first run
}

The on screen text in the repeated message degrades as the pixels start to mush out around the target area. It also happens when the background and fill values are changed.

Is this a bug? How does one put text on the screen that doesn't turn to mush with repeated calls to draw()?

My bad. I posted on the wrong board. I meant to go to Processing.org.

Please ignore.

That code worked perfectly fine for me, on a new high-end laptop running Win7.

Can you be just a tiny bit more technical in the description of the problem you are having? "Mush out" doesn't tell us anything.