Problems with Subversion, NFS and locking

Here is our setup:

We have the repository stored locally on one machine. We have several
other machines that has an active read+write mount to our SAN. We have a
symlink to this mount in /srv/library on all machines.

In /srv/library we have a working copy of our repos. When doing svn up
/srv/library on any of our machines we are able to update the working copy
used by all machines at once. Usually this works like a charm.

Some weeks ago we switched from https (webdav) to svn+ssh when talking to
our repos. Along with this switch came a locking issue. Sometimes when
running svn up we get an error that some of the directories in the working
copy we are trying to update is locked. They are not locked in Subversion
so I'm guessing it's NFS that is causing these problems. These problems
seems to occur randomly.

1: Why did this never happen when we used webdav?
2: Is there an easy way to make the locking issues disappear?

-- 
Christer Edvartsen
http://cogo.wordpress.com/