tibetan rendering support in ICU

Hi,
  I was trying to add Tibetan rendering support in OpenOffice, so
started working on icu-2.2 used in Openoffice 1.1.3 . On lines of
other modules, was trying to create one for Tibetan using this
opentype font - http://www.indlinux.org/downloads/files/Tibfont.zip . 
code files are 
http://www.indlinux.org/downloads/files/TibetanLayoutEngine.cpp
http://www.indlinux.org/downloads/files/TibetanLayoutEngine.h
 I am just trying a very basic one, with no character processing as
such, just assigning the feature tags to characters.  I am stuck at
the featureTags assignment level, where the test program gnomelayout
crashes, a crash report is at
http://www.indlinux.org/downloads/files/crashrep.txt

There has been an RFE #3617 for supporting Tibetan at
http://www.jtcsv.com/cgibin/icu-bugs/layout?id=3617
The above font only implements the GSUB features - ccmp, blws, abvs -
so trying to apply same.

Any clues to what I am doing wrong would be helpful.

Thanks,
Karunakar