I just installed xfce 4.2 from pkgsrc on NetBSD 2.0.2. I used to have taskbar on the screen downside, also the panel. The panel always was autohided to get easy access to the taskbar. As i see with the new xfce there is no "Always on top" options in the panel preferences. On this setup the autohided panel will not appear again when you click on the taskbar. Reproducible: Always Steps to Reproduce: 1. Do taskbar to bottom, not autohiding. 2. Put panel also on bottom, enable option "autohide". 3. Let panel autohide, access tasbar with mouse. Actual Results: Panel not returns from autohiding, maybe "onmouseover" doesnt work. Have to have tasbar on different position to have working autohiding panel. Expected Results: Should have worked like panel from 4.0. which had "always on top" option. GTK version is something of 2, i think.
Because of changes in the focus behaviour of the panel, this is no longer possible. If you want the taskbar and the panel on the same screen edge, maybe you could use the taskbar plugin for the panel.