hg clone - error 400 bad request ?

[John Stean]

Hello,
I am trying to move a repositories with hg clone. I moved one with hg 
clone, but when I try to move a 2nd repository using the exact same 
command I am getting :

"abort: HTTP Error 400: Bad Request"
This is on Centos. I can clone the repository to a windows box using the 
same credentials, and I can clone another repository to the centos box 
from the same location.

I have seen some online info re this possibly being a python or version 
issue - but I couldn't make much from this, I'm using 1.3.1

Any ideas? many thanks