[Closed] New style Hope HS trouble - Need mechanical advice

I'm having trouble with a hope headset. It recently developed play and when I stripped it down the cause was the lower bearing had come apart. Everything was fine with it, and I cleaned it up and pressed it back together for a nice tight reassembly. Two rides on, play is in it again, and I expect when I strip it this time it will show the same. This is a newish HS which means it has the new style of bearings they've adoped. Why is this happening?

Is it just time to replace the bearing, or have I not pressed it together properly? I 'fixed' it with a rubber mallet and some wood, but not a proper bearing press. I'm sure people have more experience with these thing than I do, so I would greatly appreciate suggestions. 15 pounds for a new bearing is the obvious route, but I'm not clear why this is happening therefore can't be sure it won't develop again.