I came across this (rather aged) thread when trying to sort out my kde4 installation. I appear to have the same startup problem as the one in the lead posting, i.e. the first (hard disk) icon on the start-up screen shows properly, then the next three icons show all together as ghost images, then the whole screen display shows a pale pink image which then disappears to leave a black screen. The startup process appears to continue, judging by the hard disk LED on the system box, but the screen remains black.
The subtle point is that this ONLY occurs when I try to start up with my 'normal' username/password from my kde3.5 days, from which I set up kde4. However, there was another user account set up under kde3.5, and I found I could still use this to boot up into kde4 without any bugs. Then, if I switch user, starting a session with my normal username, the new session starts almost normally, except that there is a brief appearance of the pink screen before the 2nd 3rd and 4th icons display in sequence, after which the start-up completes apparently normally. I have also been able to set up a new user account under the kde4 installation, which also starts up normally. I know I could shift all my /home files to a brand new username, but I would still like to know why I've got the problem with startup in my own name.
I have tried copying the .kde files from a working user account to my normal username /home directory, and although this enabled me to start up a couple of times, the system soon reverted to its failure mode.
Any advice would be welcome.