[R] error in lmLists in lme4 package (bug?)

[Elizabeth Purdom]

Hello,
I am trying to use lmLists in the lme4 package and copying over very 
standard code from the nlme package given in 'Mixed-Effects Models in S 
and S-Plus'. It appears to not accept an 'I(age-11)' in the formula, 
though it will accept the formula with out the subtraction of 11 from 
age. This seems like it would be a bug, since this is standard formula 
syntax, unless I'm missing something about lmList in lme4. Please see my 
session info and output below.
Thanks for your help,
Elizabeth

 > library(lme4)
 > data(Orthodont)
 > sessionInfo()
R version 2.10.0 (2009-10-26)
x86_64-apple-darwin9.8.0

locale:
[1] en_US.UTF-8/en_US.UTF-8/C/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base    

other attached packages:
[1] MEMSS_0.3-6        lme4_0.999375-32   Matrix_0.999375-31 
lattice_0.17-26  

loaded via a namespace (and not attached):
[1] grid_2.10.0  tools_2.10.0
 > fm1Orth.lis<-lmList(distance~age|Subject, data=Orthodont)
 > fm2Orth.lis<-lmList(distance~I(age-11)|Subject, data=Orthodont)
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found
Error in unique(c("AsIs", oldClass(x))) : object 'age' not found