directory permissions problem

I use akeeba backup for my site's backup. A few weeks ago I upgraded my FlexiContent (Joomla 1.5.26) to v. 1.5.6 (r1648). I now noticed that Akeeba throws errors when it accesses some image directories where Flexicontent stores images that are uploaded through its images field. So I checked these directories and I discovered that the directories' permissions differ from the ones Akeeba has no problems with:
All my directories are owned by the group and user php and apache are running as. All files are 644 (-rw-r--r--) and all directories usually are 755 (drwxr-xr-x). But the directories that throw errors are chmodded something else: d-wxrw--wt.
I don't know very much about file system permissions on linux but I think that means these directories are not readable by their owner but they are writable and executable to him, they are not executable by group and not readable but writable by world?
I changed the permissions of the directories in question back to drwxr-xr-x but as soon as FlexiContent drops an image into it, permissions are screwed up again. Is this a server problem or is it a bug?

Please apply this fix

flexicontent.org/forum/index.php ... pic#p34615


and you may also need to change your permissions only once manually