Hi Bald Brick
Thanks for reply. I have made a test user. And running as test user panel is ok. I got the idea that I could use settings from test user into my real home. But do not know if it is possible and what to copy. - But some weird thing is going on here because now it is working ok and really I have not rearranged anything and I have started ff via Yakuake. 
OW
PS: And I am painfully aware same thing happens with next boot. I am fully updated runnning AMD/Opteron 64 3400+ 1gb memory on old HP. 
Most KDE configuration files are in the directory
~/.kde4/share/config. The problem is just how to find the correct one. In the old days the panel had its own configuration file; these days the panel widgets are probably configured in
~/.kde4/share/config/plasma-desktop-appletsrc, but that is a guess.
Anyway, a few years ago there was a cure-all for KDE problems: remove or rename
~/.kde4 and let the system recreate it. That may still work, but even if it does you'd then lose a lot of your own settings and tweaks, so it would be much better if one could find out precisely which file it is that has somehow become misconfigured.
But if your system is working again we may not have to locate the culprit the hard way.