gvinum panic?

I'm consistently getting a system panic, trap #12 in process g_event 
when I try:

# gvinum create vinumconf

where vinumconf contains:

drive ad4 device /dev/ad4a
drive ad5 device /dev/ad5a
drive ad6 device /dev/ad6a
volume homes
     plex org raid5 336k
         sd length 50g drive ad4
         sd length 50g drive ad5
         sd length 50g drive ad6
volume services
     plex org raid5 336k
         sd length 20g drive ad4
         sd length 20g drive ad5
         sd length 20g drive ad6
volume storage
     plex org raid5 336k
         sd length 0 drive ad4
         sd length 0 drive ad5
         sd length 0 drive ad6

The same works ok with regular vinum.

I'm totally new to (g)vinum, so I could very well be doing something 
wrong here :) (ad4,5,6 are 80GB discs)

I'm running 5-STABLE from few hours ago.