Well, I THINK I have it figured out now. I went thru a lot of bad shots...but basically I am just dosing less. More like 15 grams. Also tightening the PF closer to 5:00.

It still does not explain why I got good 1st shots and not 2nd ones...

Thanks to all!

I'm having the identical problem. I got in touch with 1st-Line and they said it was the portafilter gasket; needs to be changed 1-2 times a year. But I also noticed that one of the nuts holding the grouphead was loose. The water had been squirting out between the top of the grouphead and the machine. When I tightened this down, it helped but not entirely. I'm going to try a new gasket next.

The issue of the machine running too hot/steam out of the grouphead at times is especially bad for me because I live at 7000 feet altitude, so water boils at around 190. After I steam the milk, I cool down the machine by letting water run through the grouphead until the light goes off and then pull the shot immediately. Next time I'm getting the PL042 so I can keep track of the temperature.