[R-sig-ME] possible lmer compatibility bug?

[Brandon Invergo]

Dear all,

I was just driving myself crazy trying to figure out this sudden error 
message I was getting on lines of code that were working fine the other 
day. Every time I tried to make a model with the lmer() function, it 
would return the following error: "Error in asMethod(object) : matrix is 
not symmetric [1,2]"

I realized, though, that the only thing that had changed was the version 
of R I was using, having just switched to version 2.7.1. Sure enough, 
when I loaded up v2.7.0, the script worked fine and I could successfully 
call lmer.

Is there something I'm possibly doing wrong that's preventing it from 
working in 2.7.1? Or is this a known problem?

Regards,
brandon