I was going to post this under Gentoo, however, this issue effects all distros who are using newer kernels (>=2.6.15 AFAIK). The fix for this is posted on quite a few sites and its quite simple. Close K3B, run:

ulimit -l unlimited

Re-open K3B and burn. A few other fixes I've seen, but not tested, include adding the option use-the-force-luke=bufsize:16m in K3B's config section or changing the buffer size to a value between 30-64MB. Try not to exceed 64MB or you may run into some system stability issues.



From http://fy.chalmers.se/~appro/linux/DVD+RW/tools/:

IMPORTANT NOTE for 6.0 users! Newer Linux kernels have ridiculously low default memorylocked resource limit, which prevents privileged users from starting growisofs 6.0 with "unable to anonymously mmap 33554432: Resource temporarily unavailable" error message. Next version will naturally have workaround coded in, but meanwhile you have to issue following command at command prompt prior starting growisofs:

• if you run C-like shell, issue 'limit memorylocked unlimited';
• if you run Bourne-like shell, issue 'ulimit -l unlimited';