Predict method for lmer

Hi all,

I am struggling to use predict.merMod to generate predictions from a 
relatively simple mixed model. 

Example code follows:

mer0 <- lmer ( top ~ 1 + (1|stand), data=data)
mer0.1 <- update( mer0, .~. + (1|species))

mer2 <- update(mer1, .~. + (DBH|Species)
predict(mer2, newdata=data, allow.new.levels=T) # This fails with the 
following error:

Error in t(.Call(Csparse_dense_crossprod, y, t(x))) :
   error in evaluating the argument 'x' in selecting a
 method for function
't': Error: Cholmod error 'X and/or
Y have wrong dimensions' at file ../MatrixOps/cholmod_sdmult.c, line 90

It seems that I am failing to provide the proper matrix format for the 
newdata argument, but I don't necessarily see how to fix it.

Thanks in advance,

-Nathan Rutenbeck