The problem with the icons is that Xfce 4.6.1 supports the Tango Icon theme only so far. The developers said that Tango was the only theme compliant with the XDG standards (set by freedesktop.org). Because of this, we have to set Tango as the default theme for Xfce, but for some reason that makes some of other icons to dissapear (I guess they dont have a Tango icon). The hicolor theme issue is another story. The Xfce4 packages have a small snippet in the doinst.sh file for rebuilding the icons cache, however I have hit the problem with the mixer icon also, looks like some package is corrupting the cache somehow. We will have to trace that, and include the snippet in all our future packages with hicolor icons.
About that last issue Paul, I dont have a clue. I trace deps simply by doing slapt-get -i -s some_package. We can try to do some magic by parsing PACKAGES.TXT with a script, but I am not sure what are we exactly looking for.
What are the package in your cache? Maybe we can find a clue there. Also you could try launching Xfce from a terminal or with strace, maybe we can get some more debug info. It looks more like a framebuffer issue to me.
My local cache includes all the new Xfce (and related - such as dbus, etc.). I suspect that something (prime suspect at the moment is something in the deps list for deluge) has been built on a system with the new Xfce packages installed, and since they're in my local cache, they got pulled in when I allowed the deluge update. I don't think its deluge directly - the deps for it look ok, but there is something....
As for a framebuffer issue, there is certainly some interaction with the framebuffer. I normally start VL with 'vga=870' (1280x800). I installed the latest kernel, hoping that might help, and screwed up the 'vga=' line so it started in non-framebuffer mode. In that case, I lost all video output when I exited from Xfce, but the brightness wasn't affected when the machine restarted. Fix the 'vga=' command and not only do I lose video output, the screen is in dim mode when the machine restarts.
EDIT: I forgot about brightness, try to play with the xfce-power-manager package. Uninstall/reinstall, there is also a lcd brightness plugin that provides a UI for it. I think that all these features depend on hal, is hald running?
Tried that, didn't help. I think I need the function buttons, which I've not got working under Linux. I guess I need to investigate the Thinkpad buttons package (can't recall what it is called, and was too lazy to try building it before). Attempting to adjust the LCD brightness from the xfce-power-manager package doesn't help at all. Though I'm not sure that I've got the brightness plugin installed. I'll have to check that. Hald is running, so that shouldn't be a problem.
So far, I've tried installing the latest kernel (didn't help, and made the machine pretty sluggish), and the latest Intel driver, which would not load (built against a later Xorg?).
Anyway, for the moment, I have a nice new install, which is working, just so long as I don't let any trace of Xfce 4.6.1 near it, and space to install and experimental 6.0 Standard install to see the problem can be tracked. Eventually, I'll use it as a clean 6.0 Light install for building - my current build environment isn't as clean as it could be.