I can think of one two things that might be causing it:
1) OCS was not installed correctly - check $SYBASE/charsets....you should have a directory with iso_1
2) It is having a conflict with RS installing as utf8, but some other part of the install is iso_1 (e.g. RSSD).
Unfortunately, you didn't include your resource file....
Check:
rs.rs_charset
$LANG
....if your $LANG says iso_1, try using sybinit.charset = utf8 at top of file.