[R] Using plyr and segmented together - output problem

[Ken Minns]

I am using the package segmented to fit a simple breakpoint regression 
to a large number of sets of x,y data. I have used ddply in the package 
plyr to allow me to run many data sets and gather the results into a 
data.frame. When I run it I get 3 rows inserted in the output data.frame 
for each set of data. The middle row contained the correct results (I 
cross-checked by running a single data set) while all but the degrees of 
freedom is correct in the other two rows. Help.