Due to
IDEA-16435, I perform my switches outside IDEA, using tortoise svn. However, after the switch is complete and IDEA finishes refreshing the files, the project still appears to be on the old branch (using the only available method of invoking an update and checking the paths in the update dialog).
It's only after I do a (redundant) update to the desired branch from IDEA as well that the new branch location is acknowledged by IDEA.
That is:


1. open project in IDEA
2. svn info: http://svn/branches/xxx
3. svn switch http://svn/trunk
4. update project in IDEA with Ctrl+T
5. svn info: http://svn/branches/xxx
As a result of this, a file may be edited in a wrong directory which may lead to undetected loss of changes.