Got the Email today from Jotul.. a little cut and paste.
"We've conducted a test of some of the biomass bricks available as fuel for
woodstoves that are currently available on the market. The results of the
test indicate that there is a likelihood that over firing of a Jøtul
woodstove can occur with the use of biomass bricks as a fuel in Jøtul
woodstoves. Jøtul recommends the use of seasoned natural cordwood as fuel
for it's wood-burning products. If you sell these products please be aware
of the potential for over firing."
"We've conducted a test of some of the biomass bricks available as fuel for
woodstoves that are currently available on the market. The results of the
test indicate that there is a likelihood that over firing of a Jøtul
woodstove can occur with the use of biomass bricks as a fuel in Jøtul
woodstoves. Jøtul recommends the use of seasoned natural cordwood as fuel
for it's wood-burning products. If you sell these products please be aware
of the potential for over firing."