[R] unable to install for r-base dependency?

[tkobayas at indiana.edu]

Hi,

I have been trying to install R for Ubuntu linux. Strangely, I got the 
dependency error message below.

Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
  r-cran-cluster: Depends: r-base-core (>= 2.7.1~20080614) but 
2.7.0-1gutsy0 is to be installed
E: Broken packages

This is my first time I see dependency issues in installing R on Linux. 
Does anyone help me to solve this? It seems version numbers do not 
match (r-base 2.7.0 and r-base-core 2.7.1)......

I used 'sudo apt-get install r-base....' in a terminal and used 
'synaptic manager' as well.

Thank you very much.

Taka