Maybe doing something like export LD_ASSUME_KERNEL=2.2.5 before starting xmms might help? If it does, then redo the nVidia drivers, but pass --force-tls=new to the installer.
I remember a very few people who couldn't get the installer to detect their glibc / kernel TLS support correctly; you might be having that same problem. Maybe. Try the LD_ASSUME_KERNEL thing first.