I just finished installing Fedora Core 3 as a single-boot system on a Compaq Presario PC with an 800 MHz Celeron processor. I'm not sure what video card it has, but I'll take a look if that will provide any useful information. The monitor I'm using is a pretty generic low-end LCD flat screen with 1024X1280 display.

When X launches, and any time thereafter, e.g. starting Gnome or KDE, the GUI widgets don't respond correctly, remaining invisible most of the time. To see menus, for example, I have to float the cursor over each item in the invisible menu before that item becomes visible.

If I manage to launch an application window, it typically remains invisible until something forces it to draw some portion of itself. E.g. if I happen to float the cursor over the area where any of the window controls are (like the min/maximize buttons), the title bar will appear. If I float over any buttons in the window, they will appear as I find them. The window graphics typically never appear, unless I happen to drag an invisible second window across the first window (by dragging its invisible title bar), and then as the portions of the lower window are uncovered, they might redraw themselves - but not consistently for all window types.

Even Desktop icons are invisible until I happen to find them by floating the cursor over them.

Has anyone ever seen this or have any idea what is wrong?

The hardware is okay. This machine was running Win2K when I got it, and then I had SuSE Linux on it for a few weeks before deciding to switch to Fedora. The GUIs were all fine with these other OSs.

I've tried setting the monitor type to the most benign setting I can, e.g. "Generic CRT", but that doesn't change anything (I've also tried "Generic LCD 1024X1280", of course).

Any suggestions would be very welcome, as this machine has just become unusable.