Commit fails on locked files

Hi,

I am experiencing a problem that has been reported a couple of times accross the web.

1. new file
2. add file
3. commit file
4. lock file
5. modify file
6. commit file

and that last commit fails with the following error :

Cannot verify lock on path '...'; no matching lock-token available.

[cid:part1.03020408.00020306_at_thalesgroup.com]

I am certain no one stole the lock and I am also certain that, locally, only one working copy has the lock.

I found one possible explanation that doesn't help much actually. It says you should compile the apache server with the option -enable-pie. http://subversion.1072662.n5.nabble.com/Subversion-Llocked-file-could-not-able-to-commit-the-changes-td137837.html

Has anyone experienced this ? Could anyone provide an explanation / solution to this problem ?

Thanks in advance,

Rami Houdroge