Neil,
> If I go into the new project where a colleague has added some new
> issues, I can't see those either.
>
> I can access any issue by entering an issue id # in the search box at
> the top right of the toolbar.
>
> No other users are having any problems, and I am not the only
> Administrator.
>
> Any idea what's wrong?
>
Like we discussed on IRC (irc.freenode.net, #eventum for those who don't know),
the problem here was a bug in Eventum 1.2.2 that didn't separate the search
parameters correctly on a per-project basis. To fix that, you can either upgrade
to a newer release, or click 'Clear' after switching projects.
Just archiving the solution here for future reference.
--Joao