thank you very much for your fast help! Yes, I also coudn't believe that the CF card is the problem... But another try would be to install Windows oder another Linux distribution on that CF card, because I can't answer the question, why the ebox could read the CF card until the grub loader?!? The grub loader is already on the CF card, isn't it?
Thanks also for your Trascend CF card suggestion. But this is only a 4GB card and I'm searching for a 8GB CF card, because the 4Gigabytes only have capacity for about 4 years of data with a full Davis Vantage Pro 2. Furthermore I read in this forum that the Transcend cards aren't really reliable?!? Do you have personal expierence with these Transcend cards? Price is not so important for me, reliability is more important!

Thank you very much!
Akio