Mac usage with ICC and timestamp

I have been unable to get xboard to work with ICC and timestamp on Mac
(Lion). ICC does not publish a Mac timestamp (note - the xboard docs should
be corrected in this respect) but there was a build of 4.6.2 here:
http://www.open-aurec.com/wbforum/viewtopic.php?f=19&t=50428 by Darklord42
that said it had an embedded timestamp.

Unfortunately, when I installed that build, attempting to connect to ICC
via

xboard -ics -icshost chessclub.com -icshelper /Applications/Xboard/timestamp

just gives the error "timestamp: Permission denied" even though timestamp
file has permissions -rwxr-xr-x . That timestamp, however, does work
normally called alone from the command line via ./timestamp 207.99.83.228
5000

Can someone indicate how to get xboard on a Mac running with timestamp on
ICC?