Hello,
I have searched various forums (Virtualbox, Ubuntu, Linuxquestions) for this problem I am having. I have seen it addressed in only one thread in Ubuntu without solution here in a closed development forum:
http://ubuntuforums.org/showthread.php?t=568710

and once in a virtualbox forum without solution. My problem is that under seamless mode, my windows xp guest taskbar covers my Kubuntu 7.10 KDE taskbar at the bottom as if it does not "see" the KDE desktop. I would have attached a screenshot, if I could figure out how to attach png image to this post (sorry).

How I arrived at this problem: When I had Kubuntu 7.06 (host) with Virtualbox 1.5 (not the ose) and 1.4 guest additions, I had no problem with the windows xp guest taskbar fitting nicely atop the host KDE taskbar in seamless mode. I then upgraded from 7.06 to 7.10 Kubuntu, got Virtualbox to use the latest kernel, and the problem started. At the time of upgrade, I selected the Nvidia restricted driver, but thinking that this may be the problem, I have since uninstalled it. I'm sure the Compiz desktop effects are not going, as it is an older computer, and I looked to see that nothing has been installed on the Adept manager that has anything with Compiz in the name. I have made sure that the screen resolution of 7.10 is the same as the resolution in the guest windows xp. Continuing to look for a solution, I next upgraded the guest additions to 1.5, then Virtualbox to 1.52, then the guest additions to 1.52. None of these efforts changed anything. The virtual machine itself actually works fine; it's just the annoying, and unmoveable, location of the windows xp guest taskbar that has been the issue since I upgraded from Kubuntu 7.06 to Kubuntu 7.10. I guess I should be thankful, actually. Any help would be greatly appreciated. Thanks, Frank