I noticed that erratical behaviour too. I use an extra panel on the left side of my desktop, which contains 20 icons of programs I frequently use. To group these into logical units, I need to use spacers [1]. Now, when I log in, some of the icons (the lower ones) get jumbled, seemingly randomly (although I admit that I did not investigate whether theres a rule to the altered positioning).
I can add that it's only the lower eigth icons that get jumbled. My setup is something like this:
spacer (sp) | group of 2 icons (2) | sp | 2 | sp | 8 | sp | 1 | sp | 2 | sp | 3 | sp | 2 

making a total of 20 icons, of which one is a colorchooser plasmoid split into two icons.

[1] I did not have to use something like a spacer in KDE 3.5 since I could _easily_ place an icon in any position on the panel I wanted. The workaround using spacers, in my opinion, is unnecessarily complicated and very unintuitive. I understand they can have rubber lengths, but in my opinion, one should be able to put an icon in a fixed position. Of course, if someone really wanted to use spacers as they are now, an option would be needed which decides if an icon is fixed or floaty.

I have been running revision 1044119 of kdebase for almost 2 weeks without this problem. Can you confirm this tomm?

I will upgrade shortly to check if it still works as expected.

I will try to upgrade as soon as possible (I hope OpenSuse hat those updated packages already), reorder my icons, then watch them closely ;o)

Well, I don't know what version (revision?) of kdebase it is that you're referring to, but I upgraded to version 4.3.3, reordered my icons, and after the next login, the lower ones were jumbled again. 
Btw. I have an eyedropper tool on the panel which consists of the eyedropper icon and a circular spot icon containing the last colors picked. These combined icons are displayed erratically, i.e. part of the first icon covers a completely different icon (amarok in this case), and the second part covers the amarok icon completely. So this icon is not assigned enough space on the panel, which I suspect might be (part of) the problem of this strange icon-jumbling behaviour.
Do you also have this eyedropper tool on your panel?

I will remove this tool, reorder the icons and see what happens...

I am running KDE 4.4 pre-alpha.

I see. But I removed the eyedropper tool now, logged out and in again, and everything is in place. I'll be watching it over the next days, but I'm quite confident it will hold. This would mean, I'd have to open another bug report on the eyedropper tool (or color chooser? I don't know what the correct english name is) in panels (or maybe other widgets too).

I logged in today, the lower 7 icons are jumbled again :o( The upper sixteen items (icons and spacers) seem to stay in place. Maybe I should open a second panel and populate it with only 16 items...

Maybe it could have to do with the width of the side panel. Sometimes I noticed on KDE startup, when the desktop is still spawning, that the icons in the panel are much bigger than the panel width, but once everything is completely up and running, the icons' sizes are normal again.

I've also seen this without spacers. Here's a description of my problem:


- If I have a panel with small sized applets (icons and systray, etc), the last ones on the panel (right side) change place at each logout/login.
- If I add a big spacer or a Task Manger, then everything is kept in place, but only if the spacer occupies a right sided position. If I move it to the left and leave the right side only with small sized applets, then everything jumps around once more.
- If the spacer is small (the aprox. size of an icon), then it doesn't matter where it is: everything jumps around randomly.

My guess is: the problem is somehow related with having applets in a specific place at the panel.

*** Bug 212041 has been marked as a duplicate of this bug. ***

in 4.4 the panel saves also the actual icon order, isn't anymore only based on the geometry, so should be a lot more reliable now