Sorry can't really answer your desktop problem as I don't use kde. I only use lxde, that also I am half cooked as far as the knowledge of desktop is concerned.

However I do want to highlight that as far as I know KNOPPIX has a serious shutdown problem, especially NTFS, based on my knowledge of knoppix 6.2.1/6.3. I believe it's the same for knoppix 6.4.3. I did do some post here but unfortunately nobody seems to be thinking the same as me. But there again, this is just my personal view, others may feel differently.