Version: (using KDE 4.4.3)
Installed from: Debian testing/unstable Packages
Since KDE SC 4.4 the launcher and menu icons in the panel shrink at some point when the panel gets higher. All other widgets expand like they should.
In 4.3 I had panel icons in size 48x48 (roughly) and a two row system tray. In 4.4 the same panel height shrinks the icons to size 32x32 so I have tiny centered icons in a "big" panel. When I shrink the height of the panel so that the systemtray gets one row the launcher and menu icons expand to nearly 48x48 (but still a little smaller than the maximal size in 4.3).
So having acceptable "big" icons leads to a smaller pager in the panel (which makes it hard to recognize the windows) and to a one row systemtray which needs unnecessary horizontal space. And when I want to have a two row systemtray and an acceptable big pager I get those tiny laucher and menu icons.
You might see this as a duplicate of Bug 193756 which requests that the icons in the panel always expand to full panel height. I tend to see this as a regression and something worse because the icons not only don't expand but shrink when they get more space which shouldn't happen at all.
As Bug 226039 is marked as a duplicate of Bug 193756 and therefore Bug 193756 now also seems to treat this bad usability regression I mark this one as a duplicate too.
*** This bug has been marked as a duplicate of bug 193756 ***