CVS generates lots of "*** %n in writable segment detected ***" messages

[Tania Banerjee Mishra]

Hi,
The version of my CVS server is: 1.12.13, and client is: 1.11.23. I am 
running the following st of commands:

cd
mkdir rocflu
cd rocflu
export CVSROOT=:pserver:tmish@10.5.63.176 
<mailto:tmish@10.5.63.176>:/usr/local/cvs
cvs login cvs import -m "Rocflu initial" rocflu ccmt start

So far, things worked fine. When I try to checkout rocflu from ~/work
cvs co rocflu

I am getting:
*** %n in writable segment detected ***
*** %n in writable segment detected ***
*** %n in writable segment detected ***
*** %n in writable segment detected *** [...]
*** %n in writable segment detected ***
Terminated with fatal signal 11 Core dumped; preserving 
/tmp/cvs-serv30159 on server.
CVS locks may need cleaning up.

Please let me know if you have any insights to this problem.
Thanks,
Tania