[R] data.frame error message

[Nic Ellis]

Dear R users,

I am using v2.0.1 on Windows 2000.  I have read a ".dat" file with several 
vectors, including 2 factors (2 levels x 3 levels), and a vector of 
responses, into R. There are no unique row names.  When I try plot(x,y) or 
lm(y~x) the following error is returned:

Error in model.frame(formula, rownames,...extranames: variable lengths differ

What am I doing wrong?  I am a new R user, and I didn't figure it out from 
the sections on data.frames in Dalgaard, Venable/Ripley, or simpleR, or the 
help threads.

Thanks-

Nic Ellis
Penn State