R help - Dec 2009 - plm – tests of poolability – error: insufficient number of observations

Hi everyone!

I?m running the pooltest in plm package, like this
pooltest(cstfin12~lmaccdiscrz+lcobjur+lliq+lcollateral+ldimensao, 
data = dados3,
model = "within")

But I got the following error:
Error in FUN(X[[1L]], ...) : insufficient number of 
observations

My data is an unbalanced panel with 20907 observations 
(6971 individuals and years 2001 to 2007).   This is not 
enough? Could anyone help me?

Cec?lia Carmo (Universidade de Aveiro ? Portugal)