This is the largest change they've done in years, and required the most coding to adapt to the dual-icon forecasts for 6-hr periods. I've had great fun crafting the DualImage.php from scratch to mimic what their version does on their website.
Likely, there will be more tweaks to advforecast2.php V4.x as they tweak their printable-forecast page. Right now, it's produced in HTML 4.0 format (and wouldn't pass any validation) -- the script has to convert it to XHTML so it can pass muster