http://bugs.winehq.org/show_bug.cgi?id=10142
--- Comment #14 from Greg Flint grackleflint@hotmail.com 2008-06-24 06:56:37 --- I may have a hint as to the core cause of this issue. In an attempt to sort out the problem, I copied the Guild Wars directory from Linux to a Windows box and found that the main GW window was starting up minimised.
It seems very likely that the disappearing window bug is in fact a problem with Wine displaying a minimised window. For whatever reason, the minimised window is not shown on the desktop manager's task bar nor is it displayed anywhere on the X display. This is also consistent with the window "disappearing" when you switch desktops as some Windows programs will automatically minimise if you Alt-Tab from full screen mode (GW does this).
Even though GW was running in a window when it initially disappeared, it's likely that the message sent to the program to indicate that the desktop had switched was interpreted as an Alt-Tab or equivalent so it minimised the window and then X and/or the desktop lost track of the window.
If it helps, the problem seems to be that the minimised window size is set to an something like 0 by 0. I can no longer run this GW install in windowed mode, even under XP. GW remembers the last size of the window and will automatically switch back to the previous size when you switch between windowed and full screen modes. I suspect that the bug somehow caused the window to have an insane size which GW remembered when I killed it on Linux. It is now not sanity checking this value and whenever I try to restore the window, it's setting the size to this insane value and both XP and Wine are refusing to display the broken window. On XP I can get around this by maxmimising GW from the taskbar but the broken window doesn't appear on the taskbar under Wine.
I have verified this behaviour by switching GW to full screen under XP, quitting and then loading the same GW config in to Wine. GW now starts up fine in full screen mode and behaves perfectly. If I attempt to go back to windowed mode, the GW window disappears entirely, including from the taskbar.