Firstly current is presently with KDE 4.2.4 - not 4.3.
I am able to right click on the desktop and go to Appearance Settings and under Desktop Activity i select folder view and am able to see a home folder and a trash bin appear on my desktop.
I have noticed this. The "other" users apart from my primary user just show whatever is in that users ~/ directory whereas my first user shows /home and /trash directory icons. I've tried going to "folder view settings" on my right-click desktop but no fix here.
This also happens with other distros I run KDE4 in VM's so it's not a Slackware bug but KDE4 itself if anything. KDE4 is still very much a beta release and has lots of little quirks still in it so don't expect it to be rock solid. As well I'm no expert in KDE anyway but can see some niggley problems with it.