It happened this morning again. For some reason the problem is more likely to happen on Mondays it seems. There was no PSD crash neither during Fridays close of this PSD project nor while opening it again this morning. Resources were sure sort of scarce during closing as well as during opening, however like most other applications PSD should be able to deal with that gracefully and not mess things up randomly.
Please suggest the next steps about how to finally get this issue sorted out.

To Marco van der Linden:
I guess it would be a good idea for you to upgrade to the latest version of PSD as well, just to be sure we're really talking about the same effect with the same version here.

We'll continue to look into this.

Just had the problem again. I get it at least once a week.
Is there any timeline regarding a fix or a further diagnosis for this problem?

Upgraded to 8.0.4.1514, but the problem still exists. Having over 10 windows open and reordering them (even given them labels preceded by numbers). After closing and reopening PSD windows are sorted randomly.

Same here, have to resort about every other day.

No mercy even on ones birthday: PSD forces you to resort again and again - no matter what.

Just got two project windows sort orders all messed up again! Thank you PSD!

Almost daily my PSD windows list sort order gets messed up.

What is done about this issue?
What about the diagnostic version that I brought up in discussion here on June 23?
How else can I help PSD development to fix this issue once and for all?

In the current version 9.0.6.1665 this problem is still causing trouble. Especially when PL/SQL Developer crashes and I use an automatically saved version, my Window list order is completely messed up.

Will this problem finally be resolved in the upcoming version 10?

Version 10.0.1.1694

VERY big disappointment: windows are still re-sorted after the restart.

Window where I started SQL-select at last is always at bottom in the window-list after restart of PLSQL-Developer.