Error: "The shell is already running a command"

[Peter Masiar <peter masiar yale edu>]

MC experts, please help MC/Linux newbie:

When I am trying to run a command from MC's command line, 
MC gives me an error message "The shell is already running a command".

How to find out which command is running, how to stop it?

I know I can exit MC and it should kill all child processes (right?),
but in Linux there is always *smart* way to do it 
without rebooting and reinstalling all aps like on Windoze.

My MC is 4.5.51. I'll like to upgrade - are there somewhere 
RPMs of any recent version? We have redHat and our admin likes RPMs.

Thank you!

-- 
Peter Masiar, peter masiar yale edu, (203) 764-8131
Yale Center for Medical Informatics (YCMI), http://ycmi.med.yale.edu