I too had the problem with artsd not starting at startup but it seems to have fixed itself when I updated my KDE on last Friday the 14th. Not sure what the problem was but it is gone now for me.
I also figured out my problem with mailto links. I had entered the full path to kmail in kcontrol--Network--Email. This seems to break mailto links. Weird. Figured this out by looking at the bug reports @ bugs.kde.org -john
