[R] Problems executing cor(dataset) function in R 2.11.0 for OS X ( It works fine in R 2.10.1)

[Ruben Garcia Berasategui]

 Dear all,
when trying to replicate John M. Quick's example for correlations between multiple variables posted on:

http://rtutorialseries.blogspot.com/2009/11/r-tutorial-series-zero-order.html

with R 2.11.0 (GUI 1.33) using my MacBook Pro with OX X 10.5.8 I got the following error message


> datavar<-read.csv("dataset_readingTests.csv")
> cor(datavar)
Error in cor(datavar) : 'x' must be numeric

The funny thing is that when I tried to do the same example using R 2.10.1, it worked fine.
Any ideas regarding how to solve this problem?
Many thanks in advance,
Ruben