[R] coxme - bug / error

[Rasanga Ruwanthi]

Hello everyone,
 
Many thanks to Terry Therneau for giving me a solution for my previous problem re coxme function. 
 
Now, I am using a bigger dataset to fit the same model; random treatment effect nested within centre. I used the command
 
coxme(Surv(time, status) ~ factor(treat), data=data1, random = ~1 | centre/treat)
 
But as soon as I entered this command, R dies with an error message "R for windows GUI front-end has encountered a problem and need to close ".  I am using R in Windows, R version is 2.6.0.

Has anyone ever had this type of error? Thanks for any help.
 
Ruwanthi