graphic problem in SuSe 11.0

When I start up SuSe 11.0 I get the following message just before entering KDE: “1600x1024 60hz out of range” and nothing starts further on, so I rebooted and entered through FailSafe.
In FailSafe I controlled through Yast2/Sax and my desktop screen has been configured as 1280x1024 60hz, just like before in SuSe 10.1 en SuSe 10.3. I controlled xorg.conf, nothing mentions anything like 1600x1024, nor in any other .conf in /etc/x11/.
So I changed it into 1154x864 75hz and everything working perfectly now. But I never had this problem before and I never changed anything into 1600x1024.
My question is: what happened? Where is the mistake, I want to have my normal settings back (1280x1024 60hz) without any problem. Is this a bug perhaps? How to solve this?

Little, different, question: maybe a SuSe bug or a Mozilla bug: I cannot insert any digital signature into Thunderbird for my messages, I cannot save any messages from Thunderbird to another file. Bug again?