[R] data.table error

[johannes rara]

I'm trying to learn data.table package but I get a following annoying
error message:

> install.packages("data.table")
trying URL 'http://www.freestatistics.org/cran/bin/macosx/universal/contrib/2.10/data.table_1.2.tgz'
Content type 'application/x-gzip' length 66823 bytes (65 Kb)
opened URL
==================================================
downloaded 65 Kb


The downloaded packages are in
	/var/folders/n-/n-wPTanPGa4PpVd0bTgCOU+++TI/-Tmp-//RtmppqPptG/downloaded_packages
> library(data.table)
> cr <- data.table(cars)
> cr[speed == 20]
     speed dist
[1,]    20   32
[2,]    20   48
[3,]    20   52
[4,]    20   56
[5,]    20   64
Warning messages:
1: In `[.data.table`(cr, speed == 20) :
  This R session is < 2.4.0. Please upgrade to 2.4.0+.
2: In `[.data.table`(cr, speed == 20) :
  This R session is < 2.4.0. Please upgrade to 2.4.0+.
>

I'm using R 2.10.1 (see sessioninfo below), so why this error message
keeps popping up?

> sessionInfo()
R version 2.10.1 (2009-12-14)
i386-apple-darwin8.11.1

locale:
[1] fi_FI.UTF-8/fi_FI.UTF-8/C/C/fi_FI.UTF-8/fi_FI.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

other attached packages:
[1] data.table_1.2 ref_0.97

loaded via a namespace (and not attached):
[1] tools_2.10.1
>

-J