[R] combined random effects

[Joerg Schaber]

Hi,

I have the following linear mixed model:

y(g,i,j,k,l)=u + L(g) + T(i) + D(j) + S(k) + (TS)(i,k) + error(g,i,j,k,l)

where S(k) and the combined effect (TS)(i,k) are random effects whereas 
the rest are fixed effects.

How do I specifiy the random part of the model formula in lme(), 
especially concerning the combined effect (TS)?

Moreover, when I run the model as a fixed effect model I get the 
following error:

 > lm(logMed ~ lenAA + TREAT + DYE + SLIDE + SLIDE:DYE,data=MA)
Error in lm.fit(x, y, offset = offset, ...) :
        NA/NaN/Inf in foreign function call (arg 4)

However, when I run the model with a reduced data set it works.

In the first case I have 16512 data points whereas in the reduced case I 
use only have of it. Do I reach some internal threshold here?

Thanks for help,

joerg