The result is identical on both machines:

LANG=
LC_CTYPE="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_COLLATE="C"
LC_MONETARY="C"
LC_MESSAGES="C"
LC_ALL=

The LANG environment variable was set to "C" on Solaris 10 host, but I unset it
and it didn't help.