Opentype features problem

Hi,
I am having some difficulty with getting two Opentype layout features to
work in Indesign 1.5 and Photoshop 6. The liga feature works perfectly, but
dlig and clig don't (though they preview correctly in Fontlab 4.5.1). I have
generated the font as a CFF-flavoured OTF font using either Macintosh,
Windows ANSI or FL's standard encoding but the problem remains. Yet all the
glyphs are available under Indesign's "insert character" dialog box. When I
opened the generated font in Fontlab, the features work as expected. Putting
all the lookups in the liga feature didn't solve the problem either (and
every glyph has a Unicode number attached to it). Do the alternate glyphs
need to be named according to their Unicode index?
I am using MacOS 9.2 with ATM Deluxe 4.6.1.

Regards,

David Philpott


Feature files:
feature clig{ # Contextual Ligatures
# Latin
sub T h by Thlig;
sub T T by TTlig;
sub T E by TElig;
sub C O by CO;
sub C I by CI;
sub L A by LA;
} clig;




feature dlig{ # Discretionary Ligatures
# Latin
sub c t by ct;
sub s t by st;
sub g i by gi;
sub g n by gn;
sub g r by gt;
sub g t by gt;
sub g y by gy;
sub t i by ti;
sub t r by tr;
sub t t by tt;
sub t u by tu;
sub t y by ty;
} dlig;