As I said in the subject, the default lister always opens in details mode first, then changes to list mode, that I had selected as the default. This takes a few hundred miliseconds, so it can be seen easier on a slow PC, but it's always there. Details mode first, 150-200ms. later list mode.
It's not a huge problem, but it's annoying.
Edit: This happens in 9.0.0.0, .1, and still in .2
This happens to me as well, in both listers if I'm using a dual display.
That's right. The issue is more apparent in dual display mode.
Confirmed. It's very hard to see on my PC, even with the CPUs maxed out, but I did manage to see it. I imagine it could be irritating if your setup means it is more visible. I've filed a bug report.
We will add a popup message instructing you to blink at the appropriate time 
Nice solution. 
I'm sure people on Pentium 2 or old Pentium 3 systems for whom this delay is very annoying will love that.
I can't think of many things that wouldn't be annoying on a Pentium 2 or 3.
This was fixed in Opus 9.0.0.3