Admin errors after upgrade

[PatDeLux]

Hi,
I have been very happy with CMSMS for nearly a year, but recently I upgraded from 1.05 to 1.06, and then to 1.07, and now I have some error messages in Admin mode:
in the Content>Pages section,
when I try to edit an existing page, it gives me the following messages (links below connect to screen captures)
http://www.idevlop.com/errors/ScreenShot002.png
http://www.idevlop.com/errors/ScreenShot003.png
http://www.idevlop.com/errors/ScreenShot004.png

in the Content>File management section,
I have this error msg: http://www.idevlop.com/errors/ScreenShot005.png

in the Extensions>Modules section. I now have a warning that says:
error -- The modules folder is not writable, if you would like to install modules by uploading an XML file you need to make the modules folder have full read/write/execute permissions (chmod 777). Safe mode may also be in effect.

I have checked the file permissions which seem ok.
Any hint ? I made the upgrades by uploading the diff version.
I am using a Linux server.

Please help !