Chosen isnt applying on combo fields field sets

facing same :(

Yeah, it is. Thr problem ist the implementation of the "min width". This means, that it only applies on fields, that are greater then x. The date fields (except the day field) are smaller, thats why it's not applying. I'm going to find a solution.
However, since we made, that chosen only applies to select fields, we need to add support for the date_combo widget by date module. I added this in http://drupalcode.org/project/chosen.git/commit/4bad63f

The other problem with the minWidth property still exists. I removed the check to give smaller items the minwith, but I believe that this is not the right solution, I need to discuss this with the other maintainers.

The main problem is that the date_combo widget contains *many* different select elements. We need to ensure that we apply chosen properly to each one since it looks bad if the user has enabled Chosen for the date field, and they only see some select fields with Chosen and others as normal select fields. Now that #2210767: Add 'chosen-enable' and 'chosen-disable' classes along with corresponding FAPI property has landed it's a bit easier to actually do this recursion.

For solving the fact that by default some of the date select fields get converted to Chosen, I think we'll also need #2213231: Make it possible to force-disable Chosen for a field widget which proposed to change the default for the date_combo widget to 'Disable chosen' and it has to be manually enabled in the field UI.

Tested and committed #3 to 7.x-2.x: http://drupalcode.org/project/chosen.git/commit/070d059