Problem with R on Kubuntu

Hi,

 I installed R on a system running Kubuntu and everything
seemed to work fine about a month ago.   I tried to  use R
this morning and received the following message:

"error while loading shared libraries: libreadline.so.4: cannot open
shared object file: No such file or directory"

 I haven't been able to find a fix for this online, and was hoping
someone on the list had a solution (my apologies if I missed
an obvious solution).

Thanks for your help with this.

-John