abline error help

I am trying to add a regression line to the attached data in 2011lg12dweights. I was able to plot the data and run a linear regression (lm(weight~juliandate). When i try to add a line with the abline function, I get the error message "only using the first two of nine regression coefficients". What am I doing wrong. The sequence of code used is as follows:
regdata=read.table("C:\\Users\\owner\\Desktop\\2011lg12weights.txt", header=TRUE)
Warning message:
In abline(reg) : only using the first two of 9 regression coefficients


Ambassador to the humans
I can't reproduce your error. Have you tried exiting R, starting a clean session and trying to run your code in the clean session?