Hello,

Paul Eggert suggested in
http://lists.gnu.org/archive/html/bug-coreutils/2010-07/msg00012.html
a sequence to check.

While I will need a while to get to the debugger, Pádraig Brady suggested in a private mail: "stracing the chmod calls is probably enough."

So here is the strace, in hope that it is helpful:
 <<strace.txt>> 
Regards

Martin