Is 'kldunload msdosfs_iconv' supposed to be safe? It hangs the system.

[Yuri]

I've compiled kernel without msdosfs.
When I mount some FAT system msdosfs.ko,msdosfs_iconv.ko,libiconv.ko are 
being loaded.
When I unmount this FAT all those .ko modules stay.
'kldunload msdosfs' unloads it ok.
But 'kldunload msdosfs_iconv' hangs OS immediately making it unusable.

My guess is that there are some bugs in some of those modules.
Should I file a PR for this?

Yuri