I think you are asking for trouble by switching users.
One problem is that if changes are not all on the server when you
cunlog, there is no way for them to later get back without tokens.

Coda has a world view of a user on several computers and a single coda
userid.  Changes made when disconected or write-disconnected are later
reintegrated, and the concept of 'later reintegrated' depends on the
assumption that there will be in some reasonably timely manner a
situation where there simultaneously exists adequate network
connectivity and tokens for the same coda user that made the changes.

So, I see two ways forward for you:

1) Give up on the notion of one unix uid mapping to multiple coda
   uids, and make multiple unix accounts.

2) If you can't/won't do 1, I think you are going to end up losing.
   But to try to avoid it, do 'cfs fr .' before doing cunlog, and do
   'cfs lv .' to verify that there are no CML entries.

There are also bugs in coda when repair goes badly (or rather, when
disconnected happens due to not getting an operation acked by the
server, but the server did get it).  This may be what is biting you
now.
But, the advice is the same, and particularly to check CML status
often and get caught up before proceeding.

        Greg Troxel <gdt_at_ir.bbn.com>