Thanks blutach - I burnt a disc and it came up as "Book Type: DVD-ROM" in the log. Don't know whether it was automatic or because I changed it, just glad it worked!
Not sure if it will work from now on though, unless I change this every time... so could you please tell me where I can find this 'auto change booktype'? I couldn't find it on the normal window when I go into write mode, or when I click on the book icon.
Thanks!!!