Ah, now we're getting somewhere. I'm blaming the upgrade to 2009 and KDE, when in fact it is Compiz-Fusion.
I had Compiz-Fusion enabled in 2008.1 too but did have the window options there(!), and I specifically configured the window behaviour to shading without even touching CompizConfig.
I will now have to see if this is related to the theme/window decorations or specifically to this version of Compiz-Fusion shipped with 2009.
As always user error isn't it, I did not think it might be Compiz-Fusion up until this very moment.

The missing window behaviour settings problems appear to have their roots in Compiz-Fusion on Mandriva 2009, when you enter the Control Center, go to Hardware, and configure 3D to use Compiz-Fusion, the KDE4/Mandriva 2009 themes are installed and activated.
These themes appear to not contain these options, and Compiz-Fusions own configuration tool doesn't know what 'shade' means.
On a side note, the KDE Control Center has no icon in the default setup of Mandriva 2009, but is reachable if you run 'kcontrol' from the CLI or by creating a shortcut to this command.
In the KDE Control Center you can browse through the various options related to the appearance of your desktop, and you will notice that the theme currently in use by KDE3 is not listed/selectable/modifiable.

Note about wireless (after resume from suspend-to-ram):
For some reason, when moving to another network, you can connect fine.. but the name of the previous network is shown instead of the one you are connected to.
I have no fix for this at the moment.

I have just finished trawling through all the settings in Compiz-Config to find out if I can change how window decorations and window behaviours are configured, unfortunately I have been unsuccessful.
I still cannot change the window behaviour back to shade on titlebar doubleclick, and it seems I am also unable to change the window decorations to anything else than this blue Redhat-8-ish theme.. no matter what colour or theme or decoration I pick in the KDE Control Center.
This is becoming quite frustrating.

Ideas anyone? they would be appreciated.

KDE4 uses the System Settings applet (similar to the configuration dialog used in Kubuntu). You should have an item in the menu system at Tools > System Tools > Configure your Desktop which replaces Kcontrol. If you do not have this item in the menu system, use the ALT+CLICK "Run Command" application launcher and run the systemsettings command to open the Desktop configuration applet.

In the Look and Feel section at the top, open the Window Behavior icon.

Click the Title Bar actions tab. The first item should be Title Bar Double Click. Open the drop down list to the right and select Shade.

Click the Apply button (lower right) to save the change.

Now when you doubld click a window's title bar, it should shade as it did in KDE3.

HTH,

Thanks for replying, and i'm sorry, but you missed post #12
I'm running KDE3 on top of Mandriva 2009.0 right now, because KDE4.1 just didn't work out.

To your suggestions:
"systemsettings" does not exist on my system.
And 'Configure your Desktop' has fallen out of existance since Mandriva 2008.1 (Spring) as far as I can tell (why is beyond me, it worked great), it was not present in my previous install of 2008.1 and it certainly isn't present in a default 2009 install either.

I do have 'Configure your Computer' but the only thing related to graphics you can configure there is your Xserver and 3D settings.
kcontrol still works, but this version of Compiz-Fusion as delivered with Mandriva 2009 completely overrides anything related to decoration and behaviour. Whatever I try to set, everything is always the same shades of blue and gray, same style and decoration.
As soon as I completely disable Compiz-Fusion, I can change anything I like, but also lose the 3D accelerated desktop and nice window management features. :/

I think I read that they are not going to have a separate laptop kernel any more.
They have mainlined all the laptop code into the main kernel.
Given how many desktops have all sorts of power management these days, that is probably a good idea.

Possible, it would seem logical as laptops are more common now, and indeed power management is becoming more and more important in desktops too.
Though, then in that context I am still wondering why they (Mandriva in this case) would ship a specifically named laptop kernel on the latest release of the distribution's CD/DVD media.
Perhaps a tryout phase on their end.

Are there any more suggestions, please? thank you