I just testet davfs2 with the webdav implementaion of docmgr (http://docmgr.sf.net) and I ran into this issue:
Mounting the webdav directory works, but when trying to write a file, which I do not have write access to, I get no error. The client application (i.e. texteditor) thinks everything's fine but my changed never got written to the server and I also get no error message. This will lead to data loss!
handling of file permissions is only rudimentary in davfs2 and this may be the reason for the problem.
davfs2 usually detects missing write permissions when it tries to lock the file on the server. So the problem should not arise when you use locks.
Compiling davfs2 --with-debug and sending the debug output will be usefull in any case.
To see whether there are special problems in the communication between davfs2 and docmgr, recording the traffic with ethereal might be useful too.
I'm having same problem. What is better than davfs2, if that can't be made to work?
Let me clarify my problem. I can't even add a file to the mounted dir. It mounts fine but in readonly, even when using option rw to mount.davfs command.