I came across this today and just thought I'd let people know.
I'm on OS 10.3 with FMD7 but I think this should also work on Windows.

- created file A
- set it to multi user
- selected open remote
- saw my computer listed under local hosts & clicked on it
- saw file A & clicked on it
- a new window opened, my FM was both Host & Guest
- put Get(MultiUserState) & Get(UserCount) calcs on the screen just to
be sure

- thought I'd try something stupid
- told file A (the non guest version) to switch to single user mode
- it did it and told me the connected users aren't getting kicked off
until I close the file
- however Get(MultiUserState) now said 0 (single user) and
Get(UserCount) said 2
On import I usually only test the MultiUserState, I guess now I'll also
be testing the UserCount

Another interesting thing I noticed, I have a MAIN table with 1 record
for things like registration code, registration name, number of users
allowed etc. Instead of creating relationships to obtain the related
data, I just created global calcs since they can be referenced from
anywhere. So when a user registers the company name changes and so
does the company name global calc.
This works until your in multi-user mode;
- user 1 logs in
- user 2 logs in, runs the registration, text and global calc both
update on version OK
- user 1's copy has not updated (to be expected)
- user 2 closes files (order is important)
- user 1 closes files
- some user opens the files, the registration text field is updated but
the global calc is not

FM seems to remember the value in a global calc at the time the files
are closed which may not be correct. It does not recalculate them
until a source field is modified.