Change of home directory -> refused access

i clearly don't understand freenas permissions.
set up a freenas system months ago, seems to work fine; have all the replications/rsync/etc working great.
primary access is from windows machines.

but whenever i touch a permission i have problems.

the latest; was reading through the manual, using my freenas box to view the options etc they were describing. got to the user section, looked at my user id. it showed a home directory that i did not set intentionally.
no troubles, ill set it to /nonexistant. and i was then locked out from the shares. all of them.
could still get to the server web page of course, but all the shares refused access.

restored from a config backup (which i am very good about since i seem to get locked out often...) and all is well.

but why would changing the home directory on my account have ANY effect on permissions/access to windows shares?

bug?