I was in the same boat as you toogle - kindle dx international, at 2.3.3(431100003).
This link worked for me, from
where others did not:
None of the other links posted on these boards, claiming specifically to work for DXi, actually work (at least for me, and they would if they were supposed to, as my DX is factory-default except for the 2.3.3 update).
Note especially: if a post claims to need some 2.3.4 update first, then it is not talking about the DXi i think (the serial number on the back of my DX starts with B005A).
This update, btw, puts my DXi to "Version: Kindle 2.5 (472900057), and the "create new collection" option is available in the menu, so i guess it worked!
Thanks very much lili1989.