[R] mountain lion install, error message

[clairehewson@zen]

Hi, I have been trying to install R on my mac which is running mountain lion. It is partially working, but one error message I am getting is: 

Error in function ()  : object '.activeModel' not found. 

I cannot find anything on this by googling. It appears, for example, when I try to 'add observation statistics to data' under the 'models' menu in R commander.

I wondered if anyone might have any idea what this could mean, and how I might try and fix my installation. I have installed the various recommended additional packages, and uninstalled and re-installed R around 5 times now. I have had exactly the same performance after each installation. I'm rather at a loss at where to turn next to get things working properly. 

Thanks. 

Claire.