Error with glmmADMB and beta distribution

I am new to glmmADMB and would like to use the beta distribution with
glmmadmb. However, I keep running into the same error. The response
variable is AUC (area under the curve data) from species distribution
models which is continuous and ranges from 0 to 1. The fixed variables are
the number of variables used to build the model (continuous), spatial
extent of the distribution model (continuous), model type (factor) and
taxonomic group (categorical) and the random effect is study.

Here's the model:

model1<-glmmadmb(AUC~variables+log_area+model+taxa+(1|study),
family="beta", verbose=TRUE, data=auc);

A snapshot of the data:

study                  taxa       AUC      model variables log_area
 Araujo et al. 2005 BIRD 0.9156878   GAM         7 16.21771
Araujo et al. 2005 BIRD 0.9288596   GAM         7 16.21771
Araujo et al. 2005 BIRD 0.9254065   GAM         7 16.21771
Araujo et al. 2005 BIRD 0.8825593   GAM         7 16.21771
Araujo et al. 2005 BIRD 0.9388894   GAM         7 16.21771
Araujo et al. 2005 BIRD 0.9061483   GAM         7 16.21771

When I run the model I get this error:
Error in glmmadmb(AUC ~ variables + log_area + model + taxa + (1 | study),
 :
  The function maximizer failed (couldn't find STD file)

I'm using glmm ADMB version 0.7.2.2 with R version 2.14.2 on a Mac OS X
Version 10.6.8. I've tried including
admb.opts=admbControl(shess=FALSE,noinit=FALSE) and still get the same
error. I'm guessing there's something wrong with either the response
variable or with the overall data structure?