Version: (using KDE 4.1.3) Installed from: Ubuntu Packages I changed nothing recently, but all of a sudden this morning KDE4 was giving me a black screen (with a mouse cursor that moves OK) at log in. Googling suggested that I turn off compositing in kwinrc, and indeed that fixes the problem. What information do you need to help you find this? (Please tell me *exactly* how to provide the information you need; KDE4 is a bit of a black art to me at this point, but I can follow precise instruction, I think). I want to emphasize that I did NOT change any of the compositing effects for the past week or so, and yet this only just started happening this morning. I logged out and in several times, but each time I got a black screen. Disabling compositing in kwinrc fixed the problem.
Did you upgrade your video card drivers? P.S: which video card and drivers do you have on your system?
I expect the problem here is that Kubuntu activated compositing by default, but doesn't include the 4.2 code that detects various problems that could arise. Any chance you could try with KDE4.2(pre) ?
It is possible that there was an upgrade since the last time I logged in. I don't think that there was (I didn't notice one, and I try to keep my eye out for driver and kernel updates), but I can't with 100% certainty say that there wasn't. If there's some way to find out when a package was installed, I can find out for sure, because I could then check the date of the last package update and the date of the last login. The video card is an HIS Radeon HD4670 IceQ. The driver (if I go to "Hardware Drivers" says: ATI/AMD proprietary FGLRX graphics driver Tested by the Ubuntu developers License: proprietary The driver version seems to be: 2.8.552 (according to the ubuntu package numbers).
I don't think I can try 4.2pre; I'm dependent on what Kubuntu makes available, and this is a production machine, so it's not a machine I can experiment with very easily. If there is a list of known problem effects somewhere, I could go through and try to figure out which one is causing the problem. It is strange, though, that this problem just surfaced even though I haven't changed any of the effects since first installing KDE4 a month or so ago. But maybe it was a regression in the driver (see comment #3.
As there are Kubuntu packages available for KDE 4.2 beta 1 could you please try (http://www.kubuntu.org/node/58).
As I mentioned in comment #4, I don't have any non-production machines, so I can't try 4.2 until it's made available as part of an update. However, I have not seen a recurrence of this problem. After running for a while with compositing off, I turned it back on a couple of weeks ago after making a backup copy of kwinrc. I don't log out and back in very often, but so far there's been no recurrence.
now Jaunty with 4.2 is released. How's the state? Still an issue or solved?
I haven't seen it recur, so I suspect that it's solved.